conditions by means of X-ray spectroscopy techniques free electrons lasers characteristic time scales synchrotron light source

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1 XI th KSUPS information News from SOLARIS the first Polish Synchrotron PROGRAMME Welcome to the 11 th KSUPS J. Szlachetko Electronic structure of matter probed under in-situ conditions by means of X-ray spectroscopy techniques T. Tyliszczak Soft X-ray Absorption Spectroscopy Chemical Analysis on nanoscale I.N. Demchenko A. Burian, R. Babilas, A. Fitch, L. Temleitner L. Vasylechko, O. Pekinchak, O. Pavlovska, R. Stepchuk, Yu. Prots, D. Chernyshov Cz. Ślusarczyk A. Drzewiecka-Antonik, M.T. Klepka, A. Wolska, P. Rejmak J. Cebulski, E Sheregii, J. Polit, A. Kisiel, A. Marcelli, B.V. Robouch, M. Piccinini Elemental and orbital-selective characterization of semiconductor materials by X-ray spectroscopy - XAS, RIXS and XPS Wide-angle X-ray scattering and Reverse Monte Carlo studies of Fe80B20, Co80B20, Mg60Cu30Y10 metallic glasses Structural, electronic and magnetic phase transitions in complex oxide perovskites probed by X-ray synchrotron powder diffraction Badanie w czasie rzeczywistym procesu krystalizacji polietylenu przy zastosowaniu rozpraszania promieniowania synchrotronowego pod małymi kątami Structural studies of metal-organic ligand complexes using X-ray absorption spectroscopy Study of phonon spectra of (Cd,Hg)Te-based semiconductor solid solutions using synchrotron radiation CONTENTS V VII VIII X L-01 1 L-02 4 L-03 5 L-04 8 L-05 9 L L L W. Gawelda Status and science program of the European XFEL L R. Sobierajski Phase transitions in solids under irradiations with X-ray free electrons lasers characteristic time scales M. Waśniowska, M. Sikora, M. Dobrzański, I. Miotkowski, T. Eelbo, Z. Kąkol, A. Kozłowski Magnetic impurities in the bulk and on the surface of 3D topological insulators probed using soft X-ray spectroscopy M. Kręglewski High Resolution Molecular Spectroscopy using synchrotron light source J. J. Kolodziej, K. Szamota-Leandersson UARPES -Angle Resolved Photoelectron Spectroscopy beamline at National Synchrotron Radiation Centre SOLARIS P. Starowicz, R. Kurleto, J. Goraus, H. Schwab, M. Szlawska, F. Forster, A. Szytuła, I. Vobornik, D. Kaczorowski, F. Reinert Y. Melikhov, J. Sadowski, P. Konstantynov, M. Chernyshova, J. Domagala, T. Wojciechowski, I. N. Demchenko Momentum dependence of a Kondo Resonance in Ce2Co0.8Si3.2 Structural evolution of (Ga,Mn)As thin film during medium temperature post growth annealing manifested by XAS L L L L O O M. Pławecki Fabrication and characterization of multilayer solar cells O I

2 J. Kubacki, D. Kajewski, A. Koehl, Ch. Lenser,R. Ditmann, J. Szade H. Fiedorowicz, A. Bartnik, P. W. Wachulak, R. Jarocki, J. Kostecki, M. Szczurek, D. Adjei, I. U. Ahad, M. G. Ayele, T. Fok, A. Szczurek, A. Torrisi, Ł. Węgrzyński Application of X-ray absorption and resonant photoemission spectroscopy to study electronic states of iron through 3p-3d transition for SrTiO3:Fe epitaxial film Laboratory sources of soft X-rays and extreme ultraviolet (EUV) based on laser plasmas produced with a gas puff target O O D. Paliwoda, M. Hanfland Single-crystal X-ray diffraction at extreme conditions O J. B. Pełka High-brilliance X-ray sources: a bright future for life science studies M. Kozak, Z. Pietralik, M, Taube SAXS studies of selected flexible proteins or proteins of modular structure M. Taube, A. Jarmołowski, M. Kozak Solution structure of the plant HSP90-SGT1 complex with ADP W. Gospodarczyk*, M. Kozak Influence of microfluidic flow on amyloid aggregation of hen egg white lysozyme R. Mroczka, A. Sykuła, E. A. Stefaniak Micro-X-Ray fluorescence spectrometer with X-ray single bounce metallic capillary optics for light element analysis P. Goryl, C. J. Bocchetta, Ł. Dudek, P. Gałuszka, W. Kitka, P. Kurdziel, M. Ostoja-Gajewski, R. Różańska, M. J. Stankiewicz, K. Szamota-Leandersson, J. Szota, T. Szepieniec, T. Szymocha, A. I. Wawrzyniak, K. Wawrzyniak, M. Zając, Ł. Żytniak A. Thissen, S. Bahr, T. Kampen, O. Schaff O O O O O Solaris control and IT systems towards beamline users O New developments in small spot and imaging Near Ambient Pressure XPS S B. A. Orlowski, E. Guziewicz, B. J. Kowalski, A. Reszka Synchrotron radiation photoemission study of doped semiconductors valence band P R. Minikayev, E. Dynowska, A. Szczerbakow, A. M. T. Bell, W. Szuszkiewicz R. Rapacz, K. Balin, M. Wojtyniak, J. Szade W. Paszkowicz, J. López-Solano, P. Piszora, B. Bojanowski, A. Mujica, A. Muñoz, Y. Cerenius, S. Carlson, H. Dąbkowska The limit of CdTe solubility in PbTe and the phase diagram of (Pb,Cd)Te solid solution Atomic and electronic struture of Bi-Te films grown at various conditions by MBE method Compressibility and electronic structure variation with pressure for EuVO4: A combined experimental and computational study P. Solarz Energy transfer processes to Eu 3+ ions in K5Li2GdF10 doped with Eu 3+, Pr 3+, Tb 3+ and Dy 3+ upon VUV excitation A. Bajorek, G. Chełkowska Electronic structure of selected ternary samarium compounds A. Wolska, M. T. Klepka, I. Sveklo, A. Wawro, A. Bartnik, P. Mazalski, R. Sobierajski, J. Fassbender, A. Maziewski Local structure around Co atoms in the ion and light irradiated magnetic trilayers P P P P P P II

3 D. Klinger, I. Jacyna, J. B. Pełka, A. Reszka, E. Łusakowska, A. Wawro, M. Jakubowski, A. Bartnik, R. Sobierajski I. Jacyna, D. Klinger, J. B. Pełka, R. Sobierajski, P. Dłuzewski, M. T. Klepka, E. Dynowska, A. Wawro, A. Wolska, M. Jakubowski, A. Bartnik, I. Sveklo, Z. Kurant, D.Eichert, I. Makhotkin, S. Yakunin, A. Maziewski E. Dynowska, A. Marynowska, L. T. Baczewski, J. Fassbender, R. Böttger M.T. Klepka, A. Wolska, A. Drzewiecka-Antonik, P. Rejma, G. Aquilanti Morphological and structural modifications induced in ultrathin metallic films by nanosecond pulses from EUV laser-plasma source. Investigation of morphological and structural changes in ultrathin Pt/Co/Pt trilayers induced by nanosecond pulses from EUV plasma source Structural properties of Fe/Pt multilayers before and after ion beam irradiation XANES and EXAFS studies of bioactive metallo-organic complexes in solid and liquid state K. Lawniczak-Jablonska, A. Chruściel XAFS estimation of the catalytic centre in double metal cyanide catalysts Ż. Kołodziejska, Z. Pietralik, M. Kozak Trimeric surfactants new effective carries for gene therapy M. Skupin, Z. Pietralik, K. Sobczak, R. Zieliński, M. Kozak Structural studies of nanosystems based on zwitterionic sugar-based surfactants as innovative gene delivery systems W. Andrzejewska, M. Skupin, M. Kozak Studies of dsdna and sirna oligomers in complexes with tricationic surfactants using biophysical methods M. Kręcisz, J.D. Rybka, S. Haracz, A. Strugała, I.Zhukov, A. Urbanowicz, M. Figlerowicz, M. Kozak, M. Giersig M. A. Śmiałek, M. Łabuda, J. Guthmuller, S. V. Hoffmann, N. C. Jones, M. A. MacDonald, L. Zuin, M. -J. Hubin-Franskin, J. Delwiche, D. Duflot, N. J. Mason, P. Limão-Vieira P P P P P P P P Physical characterization of BMV capsid protein P Valence and ionic lowest-lying electronic states of small esters studied by high resolution vacuum ultraviolet photoabsorption, photoelectron spectroscopy and ab initio calculations Z. Pietralik, A. Szymańska, M. Kozak Spectroscopic characterization of human cystatin C and its mutants T. J. Wasowicz, A. Kivimaki, M. Coreno, M. Zubek K Żebrowska, M. Bagińska, M. Wojdyła, E. Salas-Colera, P. Zajdel M. Bagińska, M. Wojdyła, K Żebrowska, I. -L. Liu, N. P. Butch, P. Zajdel M. Wojdyła, K. Żebrowska, M. Bagińska, E. Salas-Colera, P. Zajdel P. Piszora, J. Darul, C. Popescu, F. Fauth Hydrogen migration in formation of NH(A 3 Π) radicals in photodissociations of isoxazole and pyridine molecules Local electronic and crystal structures of FeTe doped with cobalt Two step transition and suppression of monoclinic distortion in FeTe doped with nickel Local electronic and crystal structures of FeTe doped with nickel Li0.95Mn2.05O4 under high pressure and at elevated temperature in DAC K. Szutkowski, Z. Pietralik, M. Kozak The dynamics of micellization of gemini imidazolium surfactants studied by NMR, FT-IR and SR-SAXS P P P P P P P P III

4 Regular contribution A. Kisiel Działalność Naukowa Pracowni Spektroskopii Optycznej Półprzewodników Instytutu Fizyki Uniwersytetu Jagiellońskiego. Udział w badaniach z zastosowaniem promieniowania synchrotronowego Future conferences and workshops 73 Presenting Authors Index IV

5 XI Krajowe Sympozjum Użytkowników Promieniowania Synchrotronowego , Chorzów Organizowane przez Polskie Towarzystwo Promieniowania Synchrotronowego, Uniwersytet Śląski oraz Narodowe Centrum Promieniowania Synchrotronowego SOLARIS KOMITET NAUKOWY I PROGRAMOWY Maciej Kozak Poznań Jacek Szade Katowice Radosław Przeniosło Warszawa Zbigniew Kaszkur Warszawa Wojciech Kwiatek Kraków Wojciech Paszkowicz Warszawa Krystyna Jabłońska Warszawa Agnieszka Witkowska Gdańsk Bogdan Kowalski Warszawa Paweł Piszora Poznań Marek Stankiewicz Kraków LOKALNY KOMITET ORGANIZACYJNY Jacek Szade Jerzy Kubacki Marek Kulpa Anna Bajorek Katarzyna Balin Mateusz Dulski Anna Nowak Rafał Rapacz Mateusz Weis V

6 Honorowy patronat Prezydent Miasta Zabrze Prezydent Miasta Chorzów Dziekan Wydziału Matematyki, Fizyki i Chemii Dyrektor Instytutu Fizyki im A. Chełkowskiego Dyrektor Śląskiego Międzyuczelnianego Centrum Edukacji i Badań Interdyscyplinarnych Sponsorzy Organizatorzy Polskie Towarzystwo Promieniowana Synchrotronowego wraz z Uniwersytetem Śląskim oraz Narodowym Centrum Promieniowania Synchrotronowego SOLARIS organizuje XI Krajowe Sympozjum Użytkowników Promieniowania Synchrotronowego. Polskie Towarzystwo Promieniowania Synchrotronowego Uniwersytet Śląski W Katowicach Narodowe Centrum Promieniowania Synchrotronowego SOLARIS VI

7 News from SOLARIS the first Polish Synchrotron Mamy już pierwsze światło w synchrotronie Emilia Król* Narodowe Centrum Promieniowania Synchrotronowego SOLARIS, ul. Czerwone Maki 98, Kraków * emilia.krol@uj.edu.pl Dnia 19 czerwca 2015 r. w synchrotronie Solaris po raz pierwszy zakumulowano wiązkę elektronów i przy wyjściu do linii badawczych zaobserwowano pierwsze światło. Aktualnie wiązka krąży w pierścieniu przez ponad godzinę. Energia wiązki elektronowej wstrzykiwanej do pierścienia to 490 MeV, natomiast zakumulowany prąd to 11 ma. Rysunek 1. Obraz wiązki fotonów zaobserwowany na monitorze fluorescencyjnym przy wyjściu do linii badawczej PEEM (energia elektronów w pierścieniu 490MeV, prąd 5.2 ma). (fot. zespół Solaris) Wiązkę światła udało się zarejestrować za pomocą monitora fluorescencyjnego, który składa się z płytki miedzianej, na którą napylona jest warstwa materiału fluorescencyjnego oraz kamery CCD połączonej ethernetowo z komputerem. W celu zarejestrowania obrazu wiązki fotonów, monitor umieszcza się w jej torze. Emitowane fotony promieniowania synchrotronowego uderzają w monitor i tym samym pobudzają go do świecenia, a obraz ten rejestrowany za pomocą kamery, jest obserwowany w pokoju sterowania. Wielokrotnie musieliśmy korygować ustawienia różnych parametrów synchrotronu, w szczególności dopasować wartości pól magnetycznych wszystkich magnesów do aktualnej energii wiązki elektronowej, tak aby bez problemów mogła ona wykonać pierwszy i kolejne przebiegi po pełnym obwodzie pierścienia wyjaśnia dr Adriana Wawrzyniak główny fizyk akceleratorowy w Solaris. Kolejnymi działaniami było zsynchronizowanie magnesu impulsowego z momentem wstrzykiwania wiązki w taki sposób, aby efektywnie wprowadzał on elektrony na poprawną orbitę oraz dopasowanie parametrów wnęki rezonansowej, by umożliwić ich akumulację w pierścieniu synchrotronu uzupełnia Adriana Wawrzyniak. VII Rysunek 2. Elektromagnesy pierścienia akumulacyjnego Solaris. (fot. zespół Solaris) Następny etap prac to powolne zwiększanie zakumulowanego prądu, aż do uzyskania wartości 500 ma. Jest to proces długotrwały, gdyż układy wysokiej próżni w akceleratorze muszą zostać odpowiednio wykondycjonowane. Polega to na stopniowym zwiększaniu wartości prądu i jednoczesnym oczekiwaniu na poprawę warunków ultra wysokiej próżni, gdyż obecnie przy każdorazowym wzroście prądu wzrasta również ciśnienie w komorach. Proces ten wpływa również na czas życia wiązki elektronowej. Obecnie czas życia jest zdominowany przez rozpraszanie elektronów na cząsteczkach gazu. Jednak wraz z poprawą warunków próżni czas ten będzie się wydłużać. Kolejnym zadaniem i wyzwaniem jest uzyskanie pełnej energii wiązki, która będzie trzy razy wyższa niż aktualna i osiągnie 1,5 GeV. To działanie również jest pracochłonne, bowiem przy poszczególnych energiach należy zawsze korygować optykę wiązki. Kiedy osiągniemy już stabilną wiązkę o energii końcowej, rozpocznie się kondycjonowanie i adjustacja elementów optycznych dwóch linii pomiarowych PEEM/XAS i UARPES. Rysunek 3. Synchrotron Solaris. (fot. M. Domański) Budowa synchrotronu realizowana jest przez Narodowe Centrum Promieniowania Synchrotronowego SOLARIS przy Uniwersytecie Jagiellońskim w imieniu polskiego środowiska naukowego. Projekt finansowany jest ze środków Europejskiego Funduszu Rozwoju Regionalnego w ramach Programu Operacyjnego Innowacyjna Gospodarka na lata

8 PROGRAMME Tuesday, 1 September Registration and Reception Opening Address L-01 J. Szlachetko Electronic structure of matter probed under in-situ conditions by means of X-ray spectroscopy techniques L-02 T. Tyliszczak Soft X-ray Absorption Spectroscopy Chemical Analysis on nanoscale Coffe Break O-01 P. Starowicz Momentum dependence of a Kondo Resonance in Ce2Co0.8Si O-02 Y. Melikhov Structural evolution of (Ga,Mn)As thin film during medium temperature post growth annealing manifested by XAS O-03 M. Pławecki Fabrication of characterization of multilayer solar cells O-04 J. Kubacki Lunch L-03 I.N. Demchenko L-04 A. Burian Coffe Break O-05 H. Fiedorowicz Application of X-ray absorption and resonant photoemission spectroscopy to study electronic states of iron through 3p-3d transition in SrTiO3:Fe epitaxial film Elemental and orbital-selective characterization of semiconductor materials by X-ray spectroscopy - XAS, RIXS and XPS Wide-angle X-ray scattering and Reverse Monte Carlo studies of Fe80B20, Co80B20, Mg60Cu30Y10 metallic glasses Laboratory sources of soft X-rays and extreme ultraviolet (EUV) based on laser plasmas produced with a gas puff target S-01 A. Thissen New developments in small spot and imaging Near Ambient Pressure XPS Welcome Party Wednesday, 2 September L-05 L. Vasylechko L-06 Cz. Ślusarczyk Structural, electronic and magnetic phase transitions in complex oxide perovskites probed by X-ray synchrotron powder diffraction Badanie w czasie rzeczywistym procesu krystalizacji polietylenu przy zastosowaniu rozpraszania promieniowania synchrotronowego pod małymi kątami O-06 D. Paliwoda Single-crystal X-ray diffraction at extreme conditions O-07 J. Pełka High-brilliance X-ray sources: a bright future for life science studies Coffe Break O-08 M. Kozak SAXS studies of selected flexible proteins or proteins of modular structure O-09 M. Taube Solution structure of the plant HSP90-SGT1 complex with ADP O-10 W. Gospodarczyk Lunch L-07 A. Drzewiecka-Antonik L-08 J. Cebulski Coffe Break Poster Session General Assembly of the Polish Synchrotron Radiation Society Influence of microfluidic flow on amyloid aggregation of hen egg white lysozyme Structural studies of metal-organic ligand complexes using X-ray absorption spectroscopy Study of phonon spectra of (Cd,Hg)Te-based semiconductor solid solutions using synchrotron radiation VIII

9 Thursday, 3 September L-09 W. Gawełda Status and science program of the European XFEL L-10 R. Sobierajski O-11 R. Mroczka Coffe Break L-11 M. Sikora Phase transitions in solids under irradiations with x-ray free electrons lasers characteristic time scales. Micro-X-Ray fluorescence spectrometer with X-ray single bounce metallic capillary optics for light element analysis Magnetic impurities in the bulk and on the surface of 3D topological insulators probed using soft X-ray spectroscopy L-12 M. Kręglewski High Resolution Molecular Spectroscopy using synchrotron light source Lunch Visiting the Silesian Center for Education and Interdisciplinary Research L-13 J. Kołodziej UARPES -Angle Resolved Photoelectron Spectroscopy beamline at National Synchrotron Radiation Centre SOLARIS O-12 P. Goryl Solaris control and IT systems towards beamline users Coffe Break Conference Excursion Conference Dinner Friday, 4 September Excursion to SOLARIS the Polish National Synchrotron Radiation Center L-14 M. Stankiewicz Prezentacja synchrotronu SOLARIS Coffe Break SOLARIS Discussion Panel Closing Remarks Lunch Return to Chorzów IX

10 Witamy na XI Krajowym Sympozjum Użytkowników Promieniowania Synchro-tronowego (KSUPS), które tym razem odbywa się w Śląskim Międzyuczelnianym Centrum Edukacji i Badań Interdyscyplinarnych w Chorzowie. Szczególny charakter tegorocznego spotkania jest związany z uzyskaniem kilka tygodni temu pierwszego światła w Narodowym Centrum Promieniowania Synchrotronowego SOLARIS w Krakowie. Pierwsze promieniowanie synchrotronowe wytworzone w Polsce to efekt wieloletnich starań i procesu, w którym ogromną rolę odegrało Polskie Towarzystwo Promieniowania Synchrotronowego, a w fazie budowy Uniwersytet Jagielloński. To bardzo ważny moment zwłaszcza dla polskiego środowiska naukowców wykorzystujących to promieniowanie. Wszyscy chcemy, aby polski synchrotron umożliwiał wykonywanie badań na najwyższym poziomie naukowym. Dlatego tak ważne jest nasze spotkanie w Chorzowie i Krakowie, w trakcie którego przewidziano szereg wykładów przeglądowych, podsumowujących aktualne osiągnięcia naukowe, technologiczne oraz trendy rozwojowe z zakresu badań wykorzystujących promieniowanie synchrotronowe. Ten dydaktyczny aspekt konferencji jest szczególnie ważny dla młodych naukowców, studentów studiów magisterskich czy słuchaczy studiów doktoranckich, jako potencjalnych użytkowników polskiego synchrotronu. Równie istotna jest możliwość wymiany doświadczeń pomiędzy młodymi pracownikami nauki i doświadczonymi wykładowcami. Niektóre prezentacje zostaną wygłoszone przez pochodzących z Polski naukowców pracujących obecnie na światowych synchrotronach czy też europejskim laserze XFEL. Liczymy też na ich udział w dyskusji na temat następnych, po obecnie uruchamianych, liniach badawczych w SOLARIS-ie. Dyskusja jest przewidziana w programie wizyty w Krakowie w ostatnim dniu Sympozjum, ale będzie pewnie będzie miała miejsce w trakcie całej konferencji. Wierzymy, że efektem konferencji będzie dalsza integracja środowiska użytkowników promieniowania synchrotronowego w Polsce i wzmocnienie zaplecza dla badań przy jego wykorzystaniu. Po raz pierwszy KSUPS ma miejsce na Górnym Śląsku. To znamienne, że ten Region stopniowo zmienia swoje oblicze i stawia na rozwój edukacji i nauki, czego świetnym przykładem jest miejsce naszego Sympozjum Śląskie Międzyuczelniane Centrum Edukacji i Badań Interdyscyplinarnych w Chorzowie. Witamy serdecznie Uczestników Sympozjum i życzymy dużo dobrych naukowych i nie tylko wrażeń. Komitet Organizacyjny XI KSUPS X

11 L-01 Extended abstract Tue , Electronic structure of matter probed under in-situ conditions by means of X-ray spectroscopy techniques J. Szlachetko 1,2 * 1 Paul Scherrer Institute, SwissFEL, Switzerland 2 Institute of Physics, Jan Kochanowski University, Kielce, Poland Keywords: synchrotron radiation, in-situ X-ray spectroscopy, resonant X-ray emission, X-ray free-electron laser * jakub.szlachetko@psi.ch The study of chemical processes at in situ conditions is a challenging task due to the often extreme reaction conditions, reaction complexity, reaction time scales and low chemical sensitivity to the element of interest. The available techniques are usually too slow or insensitive to probe reaction intermediates. X-rays based techniques are an ideal tool for the in-situ study because of their penetration properties, chemical specificity and sensitivity. The X-ray absorption and emission spectroscopy (XAS/XES) or their combination, resonant emission X-ray spectroscopy (RXES), allows for accurate mapping of local electronic and geometric structures in catalytic and biologically relevant systems [1]. I will present recent advances in in-situ RXES techniques, with main focus on application to chemistry and material science. I will also discuss, improvements in chemical sensitivity as well as temporal resolution by means of high energy resolution off-resonant spectroscopy (HEROS) technique [2]. Fixed optical arrangement of HEROS methodology allowed us for subsecond measurements at synchrotron [2] and shot-to-shot spectroscopy at XFEL [3]. Finally I will discuss recent experiments at XFEL where self-amplified spontaneous emission operation of LCLS machine was employed for RXES spectroscopy on 3d metal-complexes to probe the non-linear regimes of X-ray interaction with matter. Resonant X-ray emission spectroscopy RXES, relies on second-order interaction of photon with core electrons. By tuning the incidence beam energy around an absorption edge of element, the unoccupied electronic states are probed via dipole-allowed transitions leading to intermediate atomic state. The following decay from intermediate to final state is accompanied by the emission of an X-ray. Thus the RXES technique is based on monitoring, at high energy resolution, the intensity of incoming/emitted X-ray radiation versus incoming/emitted X-ray energies. Recently at SuperXAS beamline of Swiss Light Source we developed a dispersive-type spectrometer [4] that allowed us to extend the RXES spectroscopy into the real time-resolved domain. We focused our research into the materials characterization, materials at working conditions and interaction of molecules with metal surfaces. For material characterization, we applied valence-to-core (v2c) RXES in order to probe, within the same measurement, lowest unoccupied and highest occupied electronic structure of different photo-catalytic materials. Typical v2c-rxes plane for TiO 2 anatase is plotted in Figure 1 together with main electronic states accessed by the experiment [5]. The measured spectra can be compared with full-mutiple scattering calculations for determination of main electronic states contributions to the measured X-ray signals as demonstrated in Figure 1. We showed that v2c-rxes measured with dispersive-type spectrometer allow to probe very small changes on electronic structure, which indeed have large effects on catalytic properties of the material [6]. Figure 2. (a) Schematic representation of the RXES process in a Au atom. (b) Experimental setup for time-resolved RXES. The Au2O3 powder is enclosed in a reactor cell and heated up in a reducing H2 environment. (c) Time evolution of the RXES spectra during the experiment (time-resolved RXES) and schematics of the data analysis procedure employing genetic algorithm computations. From [7]. Figure 1. (Left) TiO2 anatase RXES plane. (top) Non-resonant XES spectrum; (right) TFY- XAS versus HR-XAS extracted at constant emission energy ( ev). Right) Valence and conduction band electronic states extracted from measured RXES plane (top); calculated Ti, O, and N DOS for TiO2 and TiN (below). From [5]. In order to apply RXES technique for in-situ time resolved studies and to probe materials under working conditions, the core-to-core (c2c) transitions are used that allow for more efficient detection in combination with dispersive spectrometer for quick spectral acquisition [7]. The typical in-situ experimental scheme is drawn in 1

12 Figure 2b, used for study temperature-programmed reduction of Au 2 O 3. From the experiment a short-lived Au 2 O compound has been detected for the first time under in situ conditions. On the basis of time-resolved RXES data analysis combined with genetic algorithm methodology (Figure 2c), we could determined the electronic structure of the metastable Au 2 O intermediate species. The result was confirmed with support of DFT calculations and we found that such a structure may indeed be formed and that the expanded lattice constant is due to the termination of Au 2 O on the Au 2 O 3 structure. The in-situ c2c RXES also proofed to be ideal tool to probe electronic structure changes of surface metals interacting with molecules. We showed, that based on electronic structure changes detected by RXES with support of theoretical calculations, and it is possible to determine not only the metal density of states, but also the geometry at which a molecule bounds to the metal structure [8]. Finally, I will describe on how the high chemical sensitivity c2c-rxes allow to track at in-situ conditions interaction of Pt-based drugs with DNA structure [9]. Further prospects on technical developments for simultaneous c2c and v2c RXES spectroscopy will be described as applied to anti-cancer drug studies and binding mechanisms to DNA. Figure 3. HEROS spectra of Cu recorded for 2000 self-seeded pulses at LCLS (black curve). For comparison, we plot the calculated spectrum using the Kramers-Heisenberg relation with a Cu K-edge X-ray absorption spectrum as input for calculations. In the second part of the presentation I will focus on development of high energy resolution off-resonant spectroscopy (HEROS) in application to time-resolved in-situ spectroscopy and shot-to-shot spectroscopy at XFELs. The off-resonant excitation relates to the secondorder photon-atom interaction, in which the energy of the incidence X-ray is smaller than the binding energy of core-electron. Nonetheless, due to the photon-electron interaction, a core electron may be excited into an unoccupied state above the Fermi level. This intermediate virtual state of the neutral atom decays then radiatively, with the initial core hole being filled by another inner-shell electron. Because the total energy of this scattering process has to be preserved, the energy of the emitted X-ray is lower by the amount of energy needed to promote the core-electron above the Fermi level. Most importantly, in the off-resonant excitation regime, the shape of the X-ray emission spectrum is dominated by the shape of the unoccupied density of states; i.e. proportional to X-ray absorption spectrum [10]. By combination of off-resonant excitation regime and high energy resolution dispersive-type detection, HEROS methodology was applied to monitoring the kinetics of chemical reactions [11]. Thanks to applied scanning-free approach, tracking of chemical reactions in gas-switching or temperature programed reduction/oxidation experiments at sub-second time resolution was possible and allowed to determine intermediate species involved in reactions. Recently we demonstrated that HEROS approach is free of selfabsorption effects which very often affects the spectra measured by fluorescence X-ray absorption [12]. The fixed optical geometry of the von Hamos spectrometer has allowed us to probe the unoccupied electronic states of a solid sample using HEROS on a shot-to-shot basis at an XFEL source. The experiment was performed at the CXI experiment station at the Linac Coherent Light Source, USA, and was focused on studying the X-ray interaction with solid matter under off-resonant conditions [3]. In Figure 3 we plot experimental XFEL data for Cu metal at an incidence X-ray energy tuned to -12eV below the K-shell X-ray absorption edge. The measured HEROS spectrum is compared to the result of theoretical calculations employing Kramers-Heisenberg relation [10]. In the calculations we used an X-ray absorption spectrum measured at a synchrotron facility. As shown in figure 3, a good agreement is obtained indicating that the same electronic states are probed with HEROS at an XFEL and X-ray absorption at a synchrotron source. Finally, I will present the preliminary results from XFEL experiments where the nonlinear two-photon absorption (TPA) process in condensed matter was observed. In application at hard X-ray energies, the TPA in condensed matter was observed for the first time only recently [13]. Comparing to one photon absorption which is determined by dipole-allowed transitions, the TPA process requests changing the electron quantum number by +/-2 or 0, allowing thus to access a quadrupole or forbidden excitations. Therefore, the TPA process may allow, for example, to study quadrupole-allowed transitions in K-edge spectroscopy in 3d- or 4d-type metal compounds. However, at this point, a number of fundamental experiments have to be performed first before a real approach to applied TPA spectroscopy. [1] J. Szlachetko, Y. Kayser, Techniques: RXES, HR-XAS, HEROS, GIXRF, and GEXRF, (CRC Press, Taylor & Francis Group, New York, 2014). [2] J. Szlachetko et al., Chem. Comm. 48 (2012) [3] J. Szlachetko et al., Struct. Dyn. 1 (2014) , M. Kavcic et al., Phys. Rev. B 87 (2013) [4] J. Szlachetko et al., Rev. Sci. Instr. 83 (2012) [5] J. Szlachetko, J. Sa, CrystEngComm 15,(2013) [6] J. Szlachetko et al., J. Chem. Sci. 126, (2014) 511, K. Kollbek et al., Rad. Phys. Chem. 93 (2013) 40, 2

13 K. Kollbek et al., Appl. Surf. Sci. 281 (2013) 100, J. Szlachetko et al., RSC Advances 4 (2014) 11420, K. Zakrzewska et al., Int. J. Hydrogen Energ. 40 (2015) 815. [7] J. Szlachetko et al., J. Phys. Chem. Lett. 5 (2014) 80, J. Sa et al., Phys. Chem. Chem. Phys., 16 (2014) 7692, J. Szlachetko et al., J. El. Spectr. Rel. Phenom. 188, (2013) 161. [8] J. Sá et al., Nanoscale, 5, 8462 (2013), J. Sá et al., RSC Adv., 3, (2013) 12043, C. Lothschütz et al., ChemCatChem 6 (2014) 443, M. Zienkiewicz et al., Dalton Trans. 43 (2014) 8599, M. Zienkiewicz et al., Dalton Trans., 42 (2013) 7761, H. G. Manyar et al., Catal. Sci. Technol., 3, (2013) 1497, J. Václavík et al., ChemCatChem Comm. 5, (2013) 692, O. Safonova et al., Phys. Chem. C 118 (2014) 1974, R. Kopelent et al., Angew. Chem. Int. Ed. 54 (2015) 1. [9] E.Lipiec et al., Dalton Trans. 43 (2014) 13839, G. Berger et al., J. Biol. Inorg. Chem. (2015) doi: /s [10] J. Tulkki, T Aberg, J. Phys. B: At. Mol. Phys. 15 (1982) L435, J. Tulkki, Phys. Rev. A 27 (1983) 3375, H. Hayashi et al., Chem. Phys. Lett. 371 (2003) 125, H. Hayashi et al., Phys. Rev. B 68 (2003) , J. Szlachetko et al., Phys. Rev. Lett. 97 (2006) [11] J. Szlachetko et al., J. Am. Chem. Soc. 135 (2013) 19071, C. Milne et al. Coord. Chem. Rev. 277 (2014) 44, J. Sa, Recycl. Catal. 2 (2015) 23. [12] W. Błachucki et al., Phys. Rev. Lett. 112 (2014) [13] K. Tamasaku et al., Nature Photon. 8 (2014) 31. 3

14 L-02 Tue , Soft X-ray Absorption Spectroscopy Chemical Analysis on nanoscale T. Tyliszczak* Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Figure 3 illustrates example of a significant difference of quality of chemical analysis. A partially charged electrode of LiFePO 4 battery [2] was analyzed using the beamline STXM in real space mode and calculated spatial resolution was about 70 nm while analysis of ptychographic measurements yielded component mapping with about 6 nm resolution. Keywords: synchrotron radiation, X-ray spectromicroscopy * Tolek@lbl.gov The soft X-ray scanning microscopes are used primary for utilization of X-ray absorption spectroscopy on nanoscale. Typically, the spatial resolution is being quoted using resolution of individual images. Presently, those images can be recorded with nm resolution. Unfortunately, spatial resolution for spectroscopic analysis can be much worse. The reason for this reduction of resolution is a shape of the zone plate focused X-ray beam (Figure 1). Almost all soft X-ray microscopes are using zone plates as focusing elements thus most of the spectroscopic analysis can have limited resolution. Figure 1. Typical focused beam profile. Up to 50% intensity can be in the beam wings. Recent development of ptychography (Difraction Enchenced Scanning Transmission Microscopy) [1] can overcome the limitation in spatial resolution for spectroscopy because the beam shape is deconvoluted in the final reconstruction of images. While soft X-ray ptychography can be used for imaging with exceptional resolution of 2 nm, the application for the spectroscopic analysis is even more important because it favorable can compete with TEM/EELS analysis. Figure 3. Maps of lithiated and delithiated components of partially charged FeLiPO4 electrode from a stack of images recorded around Fe L3 absorption edge using real space imaging with 25 nm zone plate (top) and ptychography with 60 nm zone plate (bottom). Acknowledgments: This work was performed at the ALS. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH [1] D. A. Shapiro, Y.-S. Yu, T. Tyliszczak, J. Cabana, R. Celestre, W. Chao, K. Kaznatcheev, A. L. D. Kilcoyne, F. Maia, S. Marchesini, S. Meng, T. Warwick, L. L. Yang, H. A. Padmore, Nature Photonics 8 (2014) 765. [2] W. C. Chueh, F. El Gabaly, J. D. Sugar, N. C. Bartelt, A. H. McDaniel, K. R. Fenton, K. R. Zavadil, T. Tyliszczak, W. Lai, K. F. McCarty, Nano Letters 13 (2013) 866. Figure 2. Test pattern image at 1500 ev. 4

15 L-03 Extended abstract Tue , Elemental and orbital-selective characterization of semiconductor materials by X-ray spectroscopy - XAS, RIXS and XPS I. N. Demchenko* Institute of Physics PAS, al. Lotnikow 32/46, Warsaw, Poland Keywords: synchrotron radiation, XAS, XES, RIXS, XPS * demch@ifpan.edu.pl The ability to control the physical properties of novel materials, by controlling crystallographic structure, arrangement of atoms inside sample's volume and along the surface taking into account point defects, is of crucial importance nowadays from both fundamental and applied research points of view. As electronic structure ultimately determines physical properties of matter, it is natural to anticipate that knowledge of it for existing systems together with the ability to describe and predict it for new systems will bring progress in science and technology to a new level. Among the ways to reach such information X-ray spectroscopy techniques stand considerably out due to their capabilities to provide detailed information on material electronic structure and thus helping us to construct the informational bridge between the structural and electronic properties of wide class of materials. This communication focuses on just a few (out of plenty) techniques, namely X-ray absorption/emission spectroscopy, Resonant inelastic X-ray scattering, and X- ray photoelectron spectroscopy and their application to characterize semiconductor materials is presented with examples. 1. Application of X-ray spectroscopy to highly disordered systems. Opposite to the very extensively studied As-rich GaNAs alloys much less work has been devoted to highly mismatched alloys (HMAs) on the N-rich side of this alloy system. In these studies a highly mismatched GaN 1 x As x alloy system was successfully synthesized in the whole composition range using a nonequilibrium low temperature molecular beam epitaxy technique [1]. In addition to other techniques X-ray spectroscopy was utilized to determine the reorganization of electronic (around Fermi level) and atomic structure of novel GaN 1 x As x system in the whole composition range. Examination of atomic structure by X-ray diffraction for the most part of samples was impossible since obtained films had no long ordering, i.e. had amorphous structure. It is an important fact that crystallinity is not required for X-ray spectroscopy measurements, making it one among a few structural probing techniques available for noncrystalline and highly disordered materials, including solutions. The optical gaps of the GaN 1 x As x alloys were measured by absorption using a LAMBDA-950 UV/vis/NIR spectrophotometer over the range of nm. It was shown that the films in the composition range of 0.17<x<0.75 are amorphous while those outside this range are crystalline (either single crystalline or polycrystalline). The composition dependence of the optical band gap energy for both crystalline and amorphous GaN 1 x As x alloys were compared directly with calculated composition dependence of the band gap. It was shown that the band gap values for the amorphous GaN 1 x As x alloys cannot be explained by the virtual crystal approximation (VCA) or the fitted curve using a single bowing parameter of 16.2 ev. Simultaneously, excellent agreement can be observed between the band gap values for the crystalline alloys and the band anticrossing (BAC) model [1-2]. The deviation of the experimental optical absorption results from the BAC calculations found for the amorphous alloys is not unexpected as the model has been developed for crystalline materials. Additional uncertainty is introduced by the fact that the band gap has been calculated as a composition weighted interpolation of the BAC model results and is less accurate for the alloys in the middle range of compositions. Figure 1. Composition dependence of the CBM and the VBM energies for GaN1 xasx alloys as measured by XAS and SXE, respectively, plotted together with the BAC predicted values. The linear interpolations of CB and VB between end point compounds (GaN and GaAs) are also shown. The positions of the H2 O2 redox potentials with respect to the VBM of GaN are also shown. According to the BAC model the observed reduction in the band gap can be attributed to an upward shift of the valence band edge (VBE) and a downward movement for the conduction band edge (CBE) in the N-rich and As-rich GaN 1 x As x alloys, respectively. However, the absolute movement of the conduction band (CB) and valence band (VB) of the GaN 1 x As x alloys cannot be derived from conducted optical measurements. To examine electronic structure of investigated system around Fermi level the combination of soft X-ray emission (SXE) and X-ray absorption (XAS) spectroscopies with the following interpretation of obtained results were done. XAS and SXE directly probe the partial density of states (DOS) of the CB and VB, respectively [1]. Overlapping the SXE and XAS spectra

16 with reference to the core level provides a direct measurement of the energy positions of the VB and CB states in semiconductor materials. For this purpose, the nitrogen K-edge (around 400 ev) was investigated at room temperature at the Advanced Light Source (ALS) on beam line XAS was detected by the total fluorescence yield detection mode with an energy resolution of about 0.2 ev, and SXE was measured using the Tennessee/Tulane grating spectrometer with a total energy resolution of 0.6 ev. The absolute positions of the CBE and VBE are directly measured as a function of composition and compared to the results of conventional optical measurements [1]. The composition dependence of the CBE and the VBE energies at N sites of GaN 1 x As x alloy as measured by XAS and SXE were displayed together with the BAC predicted values (see Fig. 1). It should be pointed out here that the calculated band movements by an interpolation of the BAC model are included for comparison purposes only. Band movements in the amorphous alloys may vary dramatically from those of crystalline alloys. Both CBE and VBE are observed to shift as x increases. A jump in the VBE to higher energy for dilute As (x ~ 0.10) polycrystalline samples as compared to GaN is observed consistently with the BAC model. A second jump to lower energy is observed in the CBE upon entering into the amorphous phase (x ~ 0.17). For increasing x in the amorphous phase, both the VBE and CBE are only very weakly shifting to higher and lower energies, respectively. Finally a smaller jump in the VBE yet again to a higher energy is observed for the amorphous to As-rich polycrystalline transition (x~0.70). Not unexpectedly the smooth interpolation of the BAC model from the dilute polycrystalline regions does not explain the discontinuous energy jumps into the amorphous phase. It should be also pointed out that the band gap energies measured by XAS and SXE are lower than the values obtained by optical absorption. This may be attributed to excitonic coupling between the screened core hole and conduction electron. 2. Potential of combined soft X-ray emission and absorption spectroscopies for estimation of direct and indirect bandgaps size in semiconductors. With the arrival of high-brilliance third-generation synchrotron sources, a new approach to study the bulk band structure has been established, namely to utilize resonant inelastic X-ray scattering (RIXS). In RIXS, an electronic Raman scattering process is used to select specific excitations of valence electrons into unoccupied conduction band states. In other words, a core electron is resonantly excited into an unoccupied state at a certain k value, and the resonant fluorescence decay of a valence electron with the same k value into the core hole is detected. The observed RIXS spectrum thus contains momentum-resolved information about the occupied and unoccupied electronic states, which can be analyzed based on the Kramers-Heisenberg formalism [3]. Since the reachable information depth is typically of the order of a few hundred nanometers, study of systems with poorly defined surface properties or protective cap layers becomes possible. In order to probe the bulk-sensitive occupied valence band electronic structure, near-threshold excitation X-ray emission spectra were recorded for CdO films for excitation energies at the O K absorption threshold [4]. Main idea of this research was to demonstrate that the XES experiments are unique since they can provide direct evidence to the band structure of a semiconductor, in particular whether a semiconductor has direct or indirect band gap, without further theoretical input. Figure 2. (a) Intensity maps of normalized RIXS and partially coherent fractions of XES corresponding to (b) standard and (c) intermediate approaches. Intermediate procedure works well for visualization of branching dispersion of occupied states. The details will be discussed during the presentation. In a XES experiment the band-gap type can be determined by observing the emission spectra as a function of excitation energy. In case of a direct energy gap material, emission at the highest energy is expected for an excitation energy in the vicinity of the absorption threshold (into the conductive band minimum, CBM). As 6

17 the excitation energy increases the emission should shift to a lower energy. For indirect band-gap materials the opposite behavior is expected, i.e., a shift of the emission spectrum (namely, top of the valence band maximum, VBM) to higher energy with increasing excitation energy. In another words, as the excitation energy increases, the probing transitions get closer, in k space, to the top of the VB. Our XES/RIXS data, see Fig. 2 and [4], clearly show this tendency and will be discussed in details. Based on RSMS theory we were able to interpret the experimental XAS spectra in terms of local geometrical and electronic structures. Calculated near-edge structure for cation and anion X-ray absorption edges represents a good coincidence with experimental one. Calculated PDOS describes well all features corresponding to unoccupied states of investigated films and allows to conclude that the orbital character of the lowest energy of the CB is mostly Cd 5s-O 2p σ*. Presented RIXS CdO data set is showing a progressively varying partial k mixing of initial and final states near the threshold and thus a varying incoherent line shape. Overlapping of XAS spectrum with RIXS ones makes possible to estimate both direct ~2.4 ev and indirect ~0.9 ev bandgap values. The obtained results are consistent with the theoretical/experimental ones presented in the literature and our own optical absorption results. 3. The properties of ultrathin superconducting films by X-ray photoelectron spectroscopy. One of the fundamental problems in nanoscience research is a question about the nature of the ground state in confined systems, particularly in the case of the superconducting (SC) materials. It is well established that the reduction of the thickness of SC films leads to the superconductor-insulator transition (SIT) [5-6]. The usual assumption is that the SIT is induced by disorder which reduces mean-free path. In [7] authors demonstrate an example of the SIT for which its origin may be even more complex. The structural and magnetotransport properties in a series of Si/Nb/Si trilayers grown by magnetron sputtering at room temperature are shown. The thickness of Nb, d, is varied from 20 nm down to 1.1 nm with a fixed Si thickness of 10 nm. The high-resolution TEM and the X-ray diffraction indicate that for d > 6 nm the films are polycrystalline, while they become amorphous for smaller d. The Hall effect measurements reveal that the positive Hall coefficient, characteristic for bulk Nb, starts to decrease for d below 6 nm, and eventually changes sign into negative for d below 2 nm. The slight nonlinearity of the Hall voltage versus magnetic field is observed in the thinnest samples (d about 1.3 nm), which may indicate the presence of two types of carriers. The possible origins of this effect may include the modification of the niobium band structure or the contribution of the Nb-Si interface to the conduction. Therefore, surface analysis studies by X-ray photoemission spectroscopy were conducted to investigate the electronic structure, the valence band, core levels of related components, and the relative positions of the energy levels involved in the interface of Si/Nb/Si structures. By repeated ion etching and XPS measurements (i.e. depth profiling), the depth distribution of the elements in the investigated samples were determined (see, for example, Fig. 3). The obtained results for Nb layers with different thickness buried in Si matrix will be shown and discussed in details. (a) AC [%] (b) Sputter time (min) a-si/9.5nm Nb/a-Si/glass Sputter time (min) Nb 3d O 1s Si 2p Nb 3d Binding Energy (ev) E E E E E E E E E E+04 Figure 3. (a) Concentration depth profile of the a-si/9.5 nm Nb/a-Si trilayer at glass substrate. (b) Contour plot of Nb 3 d spectra during a depth profiling experiment. Acknowledgments: The author wishes to thank W. Lisowski (IPCh PAS) for experimental support and useful discussions. [1] K. M. Yu, S. V. Novikov, R. Broesler, I. N. Demchenko et al, J. Appl. Phys. 106 (2009) [2] W. Shan, W. Walukiewicz, J. W. Ager III, E. E. Haller et al, Phys. Rev. Lett. 82 (1999) [3] M. Rovezzi, P. Glatzel, Semicond. Sci. Technol. 29 (2014) [4] I. N. Demchenko, J. Denlinger, M. Chernyshova, K. M. Yu et al, Phys. Rev. B 82 (2010) [5] C. A. Marrache-Kikuchi, H. Aubin, A. Pourret, K. Behnia et al, Phys. Rev. B 78 (2008) [6] T. I. Baturina, C. Strunk, M. R. Baklanov, A. Satta, Phys. Rev. Lett. 98 (2007) [7] I. Zaytseva, O. Abal oshev, P. Dluzewski,W. Paszkowicz, L. Y. Zhu, C.L. Chien, M. Konczykowski, M. Z. Cieplak, Phys. Rev. B 90 (2014) (R). 7

18 L-04 Tue , Wide-angle X-ray scattering and Reverse Monte Carlo studies of Fe 80 B 20, Co 80 B 20, Mg 60 Cu 30 Y 10 metallic glasses A. Burian 1,2 *, R. Babilas 3, A. Fitch 4, L. Temleitner 5 1 A. Chełkowski Institute of Physics, University of Silesia, ul. Uniwersutecka 4, Katowice, Poland 2 Silesian Center of Education and Interdisciplinary Research, ul. 75 Pułku Piechoty, Chorzów, Poland 3 Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, Gliwice, Poalnd 4 European Synchrotron Radiation Facility, B.P.220, F Grenoble Cedex, France 5 Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, PO Box 49, H-1525 Budapest, Hungary Keywords: synchrotron radiation, metallic glasses, wide-angle X-ray scattering, Reverse Monte Carlo * andrzej.burian@us.edu.pl The atomic scale structure of Fe 80 B 20, Co 80 B 20 and Mg 60 Cu 30 Y 10 metallic glasses has been studied using the wide-angle X-ray scattering and reverse Monte Carlo methods. The Fe 80 B 20 and Co 80 B 20 samples were prepared in the form of amorphous ribbons with thickness of 0.03 mm and width of 5 mm by the chillblock melt spinning technique under the argon protective atmosphere. The bulk Mg 60 Cu 30 Y 10 glass was obtained by injection of the Mg-Cu-Y melted material in the proportion 60:30:10 into a copper mold by a pressure casting method. The wide-angle X-ray scattering measurements were performed on the ID31 beam-line at the European Synchrotron Radiation Facility, Grenoble, France. The incident beam energy of 31 kev yielding the wavelength of 0.4 Å was used in this experiment. The scattered intensities were recorded to the maximum value of the scattering vector Q = 4πsinθ/λ = 23 Å -1, where 2θ is the scattering angle and λ is the wavelength. As the atomic scale structure of the investigated materials cannot be described using formalism of crystallography an approach based on the Reverse Monte Carlo [1] fitting procedure was used. In this method Marcov chain sampling with the Metropolis accelerating algorithm [2] allows generation of three dimensional particle configuration that is consistent with the experimentally measured structure factor. The fit quality is evaluated by a standard χ 2 test in which the experimental errors are taken into account. In our previous paper [3] the local atomic arrangement in the Fe 80 B 20 glass was compared with those of the Fe 3 B, Fe 23 B 6 and bcc Fe crystalline phases. From this comparison it has been concluded that the local structure of the crystalline counterparts is not consistent with the experimental data for glassy Fe 80 B 20. The Reverse Monte Carlo method applied for the Fe 80 B 20, Co 80 B 20 and Mg 60 Cu 30 Y 10 metallic glasses allowed obtaining perfect fit to the experimental structure factors and to the experimental pair distribution functions. Resemblance of the local structure, which extends up to approximately 20 Å, to the icosahedral and trigonal prism configurations is discussed. The Reverse Monte Carlo results are compared with high-resolution transmission electron microscopy observations. From this comparison it can be concluded that both methods lead to consistent description of the local atomic arrangement in the investigated materials. Acknowledgments: This work was supported by the National Science Centre under the research project No.: 2011/03/D/ST8/ [1] R. L. McGreevy and L. Pusztai, Molecular Simulation 1 (1988) 359. [2] N. Metropolis, A.W. Rosenbluth, M.N. Rosenbluth, A.H. Teller, E. Teller, J. Chem. Phys. 21 (1953) [3] R. Babilas, Ł. Hawełek, A. Burian, J. Solid State Chemistry 219 (2014) 179. [4] R. Babilas, R. Nowosielski, M. Pawlyta, A. Fitch, A. Burian, Materials Characterization, in press. 8

19 L-05 Wed , Structural, electronic and magnetic phase transitions in complex oxide perovskites probed by X-ray synchrotron powder diffraction L. Vasylechko 1 *, O. Pekinchak 1, O. Pavlovska 1, R. Stepchuk 1, Yu. Prots 2, D. Chernyshov 3 transitions occurred in the end members of the systems. In particular, SmCoO 3 cobaltite undergoes magnetic, spin-spin and metal-insulator transitions at 493 K, 605 K and 693 K, respectively [2], whereas the SmFeO 3 ferrite shows spin-reorientation at 480 K and para- to antiferromagnetic transition at 670 K [3]. Clear sign for a magnetoelastic coupling has been detected in SmFeO 3 at the Néel-temperature of 675 K [4]. 1 Lviv Polytechnic National University, 12 Bandera St., Lviv, Ukraine 2 Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, Dresden, Germany 3 Swiss-Norwegian Beam Lines at ESRF, BP220, 38000, Grenoble, France Keywords: perovskites, phase transitions, synchrotron radiation * crystal-lov@polynet.lviv.ua In situ temperature-dependence powder diffraction examinations and analysis of thermal expansion is very useful tool not only for the study of structural phase transitions, but also for the investigation of diverse electronic and magnetic phase transformations occurred in complex oxide and intermetallic systems. Especially this is important for the Pr- and Nd-based compositions, where the spin-state transition is seen much better in the thermal expansion data than in the magnetic susceptibility due to the large contribution of the 4f moments of Pr and Nd ions on the magnetic properties. Our recent in situ X-ray synchrotron powder diffraction investigations of the mixed cobaltites-ferrites RCo 1- Fe x O 3 (R = Pr, Nd, Sm, Eu, Gd, Tb) performed at ESRF beamlines BM1A and ID22 revealed anomalous lattice expansion, which is reflected in a sigmoidal dependence of the unit cell dimensions and in abnormal anisotropic increase of the thermal expansion coefficients (TEC) with (several) broad maxima in the temperature range of K, depending on the composition. Thorough analysis of the selected bond lengths and octahedra tilt angles, as well as the atomic displacement parameters (adp s) allows to detect extra structural anomalies, which are evidently associated with the electronic and magnetic phase transitions occurred in the RCoO 3 RFeO 3 systems at the elevated temperatures. As an example, significant bond-length stretching inside Co/FeO 6 octahedra in SmCo 0.7 Fe 0.3 O 3 structure at ~450 K and at K (Fig. 1a) and corresponding extrema at the adp s curves (Fig. 1b) indicate the Jahn-Teller distortion (which may be dynamic) associated with excited spin states of Co 3+ species. According to Ref. [1] the transition from low-spin to intermediate/high-spin state of Co 3+ ions in RCoO 3 series introduces bond length fluctuation that suppresses the phonon contribution. It is evident that observed structural anomalies in SmCo 0.7 Fe 0.3 O 3, like as in other RCo 1- Fe x O 3 perovskites are associated with the magnetic and electronic phase Figure 1. Temperature dependence of Co/Fe-O bond lengths (a) and atomic displacement parameters (b) in SmCo0.7Fe0.3O3 structure reflecting a coupling of electronic and magnetic phase transitions to the lattice Acknowledgments: This work was supported in parts by the Ukrainian Ministry of Education and Sciences (project KMON ) and ICDD Grant-in-aid program. High-resolution X-ray synchrotron powder diffraction measurements were carried out during beamtimes allocated to the ESRF experiments CRG and MA [1] J.-Q. Yan, J.-S. Zhou, J. B. Goodenough. Phys. Rev. B 69 (2004) [2] K. Knizek, Z. Jirak, J. Hejtmanek, M. Veverka, M. Marysko, G. Maris, T. T. M. Palstra. Eur. Phys. J. B 47 (2005) 213. [3] J.-H. Lee, Y. K. Jeong, J. H. Park, M. -A. Oak, H. M. Jang, J. Y. Son, J. F. Scott. Phys. Rev. Letters 107 (2011) [4] C.-Y. Kuo, Y. Drees, M. T. Fernández-Díaz, L. Zhao, L. Vasylechko, D. Sheptyakov, A. M.T. Bell, T. W. Pi, H.-J. Lin, M.-K. Wu, E. Pellegrin, S. M. Valvidares, Z.W. Li, P. Adler, A. Todorova, R. Küchler, A. Steppke, L. H. Tjeng, Z. Hu, A. C. Komarek. Phys. Rev. Letters 113 (2014)

20 L-06 Extended abstract Wed , Badanie w czasie rzeczywistym procesu krystalizacji polietylenu przy zastosowaniu rozpraszania promieniowania synchrotronowego pod małymi kątami Cz. Ślusarczyk Zakład Fizyki i Badań Strukturalnych, Instytut Inżynierii Tekstyliów i Materiałów Polimerowych, Akademia Techniczno- Humanistyczna, ul. Willowa 2, Bielsko-Biała Keywords: krystalizacja izotermiczna, polietylen, SAXS, promieniowanie synchrotronowe * cslusarczyk@ath.bielsko.pl Krystalizacja jest jednym z najważniejszych procesów kształtujących strukturę i własności materiałów polimerowych. Proces ten, oprócz warunków termodynamicznych określonych głównie przez temperaturę i ciśnienie, silnie zależy od mikrostruktury makrocząsteczek polimerowych. Zasadniczym warunkiem krystalizacji polimeru jest bowiem regularność budowy makrocząsteczki łańcuchowej; polimery izotaktyczne i syndiotaktyczne wykazują zdolność do krystalizacji, podczas gdy ataktyczne nie posiadają tej zdolności. Obecność rozgałęzień w łańcuchu obniża z reguły zdolność polimeru do krystalizacji. Zgodnie z uznaną i szeroko stosowaną teorią krystalizacji polimerów, opracowaną przez Lauritzena i Hoffmana [1] i opartą na koncepcji wielokrotnego fałdowania makrocząsteczek, proces krystalizacji jest procesem dwuetapowym. W pierwszym etapie, zwanym zarodkowaniem pierwotnym, w wyniku termicznych fluktuacji gęstości lub obecności cząstek obcych substancji w stopionym polimerze tworzą się uporządkowane ugrupowania fragmentów makrocząsteczek, które stają się zarodkami dalszej krystalizacji. W drugim etapie następuje wzrost krystalitów, który odbywa się poprzez przyłączanie segmentów makrocząsteczek do powierzchni bocznych zarodków pierwotnych. Pojedyncze kryształy polimerów mogą się tworzyć podczas krystalizacji z rozcieńczonych roztworów, podczas gdy krystalizacja ze stężonych roztworów i ze stanu stopionego zachodzi na ogół w formie stosów kryształów lamelarnych, składających się z równolegle ułożonych lamel krystalicznych przedzielonych warstwami amorficznymi. Pojedyncza lamela krystaliczna w takim stosie jest równoległościanem o wymiarach poprzecznych dużych w porównaniu do grubości, która jest rzędu nm. Obszar amorficzny (interlamelarny) w stosie tworzą pofałdowania łańcuchów, końce i pętle łańcuchów, łańcuchy łączące lamele krystaliczne oraz krótkie rozgałęzienia boczne. W jednorodnym polu temperatury polimeru stosy lamel wzrastają z jednakową prędkością we wszystkich kierunkach, co prowadzi do powstawania agregatów kryształów lamelarnych, zwanych sferolitami. Do momentu wzajemnego zetknięcia się sferolity mają 10 symetrię kulistą, a ich promień rośnie liniowo z czasem. Po wzajemnym zetknięciu się i utworzeniu granic z sąsiadami, sferolity stają się wielościanami. Sąsiednie lamele w sferolicie rozdziela faza amorficzna zawierająca splątania, odgałęzienia i te fragmenty łańcuchów, które nie wbudowały się w kryształ wskutek odmiennej struktury chemicznej lub konfiguracji. Polietylen (PE) krystalizuje głównie w dwóch odmianach polimorficznych. Najbardziej rozpowszechnioną odmianą krystalograficzną PE jest odmiana rombowa. Lamele krystaliczne tej odmiany utworzone są z pofałdowanych makrocząsteczek (ang. folded-chain crystals), przyjmujących konformację płaskiego zygzaka. Pod wysokim ciśnieniem, powyżej 360 MPa, PE krystalizuje w stabilnej fazie heksagonalnej [2]. Kryształy tej odmiany utworzone są z rozprostowanych łańcuchów polimerowych (ang. chain-extended crystals), co prowadzi do bardzo dużej grubości krystalitów, porównywalnej do długości całkowicie rozprostowanych makrocząsteczek. Faza heksagonalna charakteryzuje się dużym stopniem nieuporządkowania, jej gęstość jest o ok. 8,5 % mniejsza od gęstości w pełni uporządkowanej odmiany rombowej. Słabe oddziaływania w obrębie kryształu fazy heksagonalnej umożliwiają dyfuzję makrocząsteczek wzdłuż ich osi w obrębie kryształu (ang. sliding diffusion) [3]. Na skutek tej dyfuzji kryształ odmiany heksagonalnej może w sposób nieograniczony kontynuować wzrost w kierunku osi łańcuchów. Taki mechanizm przyrostu grubości kryształu, traktowany jako element pierwotnej krystalizacji, nazwano wzrostem przez pogrubianie (ang. thickening growth), w odróżnieniu od pogrubiania uformowanych już lamel podczas wygrzewania (ang. lamellar thickening). Proces formowania kryształów z rozprostowaniem łańcuchów jest bardzo powolny i wymaga długich czasów krystalizacji. Zmniejszenie ciśnienia i temperatury prowadzi do transformacji fazy heksagonalnej do formy rombowej. Stabilność różnych odmian krystalograficznych polimerów zależy nie tylko od parametrów termodynamicznych takich jak ciśnienie i temperatura, ale także od rozmiarów krystalitów. Przejawem tej zależności jest dobrze doświadczalnie udokumentowany, a teoretycznie opisany równaniem Gibbsa-Thomsona [4], fakt zmniejszania się temperatury topnienia kryształów lamelarnych wraz ze zmniejszaniem się ich grubości. Zależność stabilności kryształów polimerowych od ich rozmiarów jest różna dla różnych odmian polimorficznych. Stąd może się zdarzyć, że faza krystaliczna o nieskończenie dużych rozmiarach, która przy danym ciśnieniu i temperaturze jest niestabilna, dla rozmiarów nanometrycznych staje się stabilna i polimer może krystalizować w tej fazie pomimo, że warunki termodynamiczne są poza reżimem jej stabilności. Dla polietylenu oznacza to, że faza heksagonalna, która, jak wspomniano powyżej, jest stabilna przy wysokich ciśnieniach, może się tworzyć również pod ciśnieniem atmosferycznym we wczesnych etapach procesu krystalizacji, gdy rozmiary krystalitów są niewielkie. W tych warunkach tworząca się faza heksagonalna jest metastabilna i po osiągnięciu odpowiednio dużych

21 rozmiarów przechodzi w odmianę rombową. Po raz pierwszy możliwość krystalizacji PE poprzez fazę metastabilną została opisana w 1994 r. przez Kellera i współpracowników [5], a doświadczalnie potwierdzona dopiero w 2006 r. przez Tracza i współpracowników [6], którzy, stosując mikroskopię AFM, zaobserwowali tworzenie się fazy heksagonalnej dla PE krystalizowanego pod ciśnieniem atmosferycznym na powierzchni grafitu pirolitycznego. Badania te miały jednak charakter statyczny, tzn. polegały na obserwacji kryształów fazy heksagonalnej uformowanych po skrystalizowaniu w danych warunkach próbki polimeru. W prezentowanej pracy przedstawiono wyniki badań procesu krystalizacji izotermicznej polietylenu przy pomocy metody małokątowego rozpraszania promieniowania rentgenowskiego (SAXS). Zastosowanie promieniowania synchrotronowego pozwoliło zbadać ten proces w warunkach dynamicznych i po raz pierwszy zaobserwować w czasie rzeczywistym przebieg krystalizacji PE poprzez metastabilną fazę heksagonalną. W pracy badano przebieg krystalizacji izotermicznej polietylenu wysokiej gęstości (HDPE) o średniej masie cząsteczkowej g/mol w następujących temperaturach [ C]: 40, 100, 110, 116, 118, 120, 122, 124. Synchrotronowe badania SAXS przeprowadzono przy użyciu podwójnie ogniskowanej kamery X33 w laboratorium EMBL na pierścieniu akumulacyjnym DORIS ośrodka badawczego HASYLAB-DESY w Hamburgu. Proces krystalizacji prowadzono w specjalnie skonstruowanej przystawce pomiarowej, składającej się z dwóch piecyków grzejnych. W jednym z nich próbka polimeru była topiona w temperaturze 200 o C, a następnie przy użyciu odpowiedniego mechanizmu, bardzo szybko umieszczana w drugim piecyku, w którym panowała dana temperatura krystalizacji. Przystawka znajdowała się na linii pomiarowej, co umożliwiło rejestrację krzywych dyfrakcyjnych już po kilku sekundach od umieszczenia próbki w danej temperaturze. Analiza krzywych SAXS została przeprowadzona za pomocą funkcji rozkładu odległości powierzchni fazowych g 1 (r) (ang. IDF interface distribution function) [7], którą oblicza się, na podstawie zarejestrowanego rozkładu natężenia rozpraszania I(s), ze wzoru: 3 g 1( r) 16 G1 ( s)cos(2 rs) ds 0 w którym funkcja G 1 (s) nosi nazwę funkcji interferencyjnej układu lamelarnego (ang. interference function) i jest obliczana ze wzoru: G ( s 4 1 s) limi( s) s I( s) s W powyższych zależnościach s = 2sinθ/λ jest wartością wektora rozpraszania; λ jest długością fali promieniowania rentgenowskiego, zaś 2θ jest kątem rozpraszania. Dla rzeczywistego układu lamelarnego funkcja g 1 (r) posiada ekstrema, z położeń których bezpośrednio otrzymuje się wartości wielkiego okresu struktury lamelarnej (LP), grubości lamel krystalicznych 4 (L C ) i grubości warstwy amorficznej (L A ). Rys. 1a przedstawia ewolucję w czasie funkcji g 1 (r) dla próbki krystalizowanej w temperaturze 122 C, a Rys. 1b przebieg zmian wielkości charakteryzujących strukturę lamelarną, otrzymanych z funkcji g 1 (r). g 1 (r) LP, La, Lc [A] 1.40E E E E E E E E E E-009 La Lc -6.00E-009 LP -8.00E r [A] 1000 Log Time [s] Rysunek 1. (a) Ewolucja funkcji rozkładu odległości powierzchni fazowych g1(r) dla PE krystalizowanego w temperaturze TC = 122 C; (b) Przebieg zmian w czasie krystalizacji w TC = 122 o C parametrów struktury krystalicznej: wielkiego okresu LP, grubości lamel krystalicznych LC, grubości warstwy amorficznej LA. Zakres zmian grubości lamel krystalicznych zależy silnie od temperatury krystalizacji, co przedstawia Rys. 2. Jak widać z tego rysunku, zależność L C od logarytmu czasu krystalizacji jest liniowa, może zatem być opisana równaniem L C = B 1 log(t) + B 2, gdzie współczynnik B 1 związany jest z szybkością przyrostu grubości lamel krystalicznych w trakcie ich powstawania. Wartość współczynnika B 1, wyznaczona metodą regresji liniowej, zależy od temperatury krystalizacji T C (Rys. 3). Dla przykładu B 1 = 71,1 ± 1,1 w temperaturze T C = 122 C, podczas gdy dla T C = 116 C wartość B 1 = 11,7 ± 1,7. Tak duża różnica w szybkości przyrostu grubości lamel krystalicznych wskazuje na odmienny mechanizm krystalizacji PE w tych temperaturach. Ponieważ duża szybkość zmian grubości lamel krystalicznych wymaga dużej mobilności łańcuchów polimerowych, takiej jaką mają makrocząsteczki PE w fazie heksagonalnej, to wynika stąd, że w temperaturze T C = 122 C polimer ten krystalizuje właśnie w tej fazie poprzez mechanizm wzrostu przez pogrubianie (thickening growth). W temperaturze T C = 116 C natomiast nie obserwuje się tworzenia metastabilnej (a) (b) LP Lc La 11

22 fazy heksagonalnej; PE krystalizuje bezpośrednio w stabilnej w tych warunkach odmianie rombowej, a obserwowany przyrost grubości lamel związany jest z typowym, często obserwowanym procesem ich pogrubiania (lamellar thickening). Tak więc możliwy jest, przewidziany przez Kellera, przebieg procesu krystalizacji polietylenu w warunkach ciśnienia atmosferycznego, w którym faza heksagonalna tworzy się wcześniej niż stabilna w tych warunkach faza rombowa tego polimeru. B Crystal thickness Lc [A] Log Time [s] T C = 40 o C T C = 116 o C T C = 118 o C T C = 120 o C T C = 122 o C Rysunek 2. Zależność grubości lamel krystalicznych LC od logarytmu czasu krystalizacji dla różnych temperatur krystalizacji izotermicznej T C [ o C] Rysunek 3. Zależność współczynnika B1 od temperatury krystalizacji izotermicznej TC. [1] J. D. Hoffman, G. T. Davis, J. I. Lauritzen, Treatise on Solid State Chemistry (red. N.B.Hannay, vol.3, Plenum Press, New York 1976). [2] G. C. Bassett, Polymer 17 (1976) 460. [3] M. Hikosaka, S. Rastogi, A. Keller, H. Kawabata, J. Macromol. Sci. Phys. B31 (1992) 87. [4] P. J. Flory, A. Vrij A, J. Am. Chem. Soc. 85 (1963) [5] A. Keller, M. Hikosaka, S. Rastogi, A. Toda, P. Barham, P. G. Goldbeck-Wood, J. Mater. Sci. 29 (1994) [6] A. Tracz, I. Kucinska, J.K. Jeszka, Polymer 47 (2006) [7] J. W. Ruland, Coll. Polym. Sci. 255 (1977) 417. [8] S. V. Krivovichev, Angew. Chem. 53 (2014)

23 L-07 Wed , Structural studies of metal-organic ligand complexes using X-ray absorption spectroscopy A. Drzewiecka-Antonik 1 *, M. T. Klepka 1, A. Wolska 1, P. Rejmak 1 1 Institute of Physics PAS, Warsaw, Al. Lotnikow 32/46, PL Warsaw, Poland Keywords: XAFS, metal-organic ligand complexes * adrzew@ifpan.edu.pl The discovery that the metal complexes, especially with transition metals like copper and silver, can be more effective than the parent ligands opened a new field of drug research. In our laboratory the synthesis and structural characterization of novel biologically active metal-organic ligand complexes is carried out. The direct, hydrothermal and electrochemical synthesis are used for complexation reactions. New compounds (copper and silver complexes) are tested for microbiological activity on standard and clinical strains of fungi and bacteria. The use of the microorganisms taken from patients is an important stage of our studies. As a result of the civilization development and the various human activities (e.g. inappropriate use of antibiotics) the mutation of infecting cells of bacteria and fungi is observed. We want to face this problem and obtain metal-based complexes with high selectivity and efficacy. The synthesized compounds are initially characterized by elemental analysis, IR and UV-VIS spectroscopies. More detailed information about the coordination sphere of bioactive complexes is obtained by applying the X-ray absorption spectroscopy. Extended X-ray absorption fine structure (EXAFS) analysis provides information about the average coordination number, the type of atoms around the metal ion and the distances between the metal center and the coordinating molecules. This data allows proposing a coordination mode of ligands to the metal cation in the studied complexes. From XANES spectra (X-ray absorption near edge structure) it is possible to determine the oxidation state of the metal in the analyzed compounds. In addition, by taking advantage of the fact that the shape of XANES spectra strongly depend on the angles between central and neighboring atoms, the analysis of these spectra allow confirmation and improvement of the coordination modes proposed from the EXAFS analysis. Moreover, the density functional theory level calculations are carried out. The theoretical study on metal complexes (geometry optimization, calculations of vibrational frequencies, simulations of UV-Vis spectra etc.) complements the experimental data. During presentation the structural studies on complexes with derivatives of coumarin (O-donor ligands) and derivatives of thiourea (N,S-donor ligands) will be presented. Acknowledgments: Experimental research was funded from the Polish National Science Centre(Grant No. UMO- 2012/07/D/ST5/02251). This work was supported in part by PL-Grid Infrastructure. P. Rejmak acknowledges EAgLE project no for the financial support. 13

24 L-08 Wed , Study of phonon spectra of (Cd,Hg)Te-based semiconductor solid solutions using synchrotron radiation frequency vs. temperature was observed for ZnTe-like and HgTe-like TO-phonon modes [5]. Since these dependencies are resonant, the phenomenon explanation is based on the modified Kawamura model [6]. J. Cebulski 1 *, E Sheregii 1, J. Polit 1, A. Kisiel 2, A. Marcelli 3, B. V. Robouch 3, M. Piccinini 3 1 Chair of Applied Physics, University of Rzeszow, Pigonia 1, Rzeszow, Poland 2 Instytut Fizyki, Universytet Jagiellonski, Reymonta 4, Krakow, Poland 3 Istituto Nazionaledi Fisica Nucleare Laboratori Nazionalidi Frascati,Via E.Fermi 40,00044 Frascati, Italy Keywords: synchrotron radiation, phonon spectra * cebulski@ur.edu.pl Let me present an overview of recent achievements made by the Polish-Italian team in our more than 15-year collaborative research on (Cd,Hg)Te-based semiconductor solid solutions. The specialized source of synchrotron radiation available in DAȹNE-light laboratory at Frascati (Italy) [1] was used for far-infrared reflection measurements FTIR. Optical TO-phonon spectra were interpreted within the framework of the Verleur and Barker model upgraded by authors [2]. In addition, the authors original methodology was applied. The final version of this upgraded interpretation model for optical TO-phonon spectra includes the following Lorentzian parameters: S i, TOi and i representing a generator capacity, phonon line frequency, and a damping factor, respectively. This model has been used to interpret a large number of phonon spectra for many semiconductor compounds such as Hg 1-x Zn x Te, Hg 1-x Cd x Te, Zn x Cd 1-x Te, Hg 1-xyZn x Cd y Te, Hg 1-x-y Mn x Cd y Te with different compositions to determine parameters S i, TOi and i of each existing mode. Phonon spectra with mercury vacancies obtained for some Hg 1-x Cd x Te and Hg 1-x Zn x Te compounds were examined and interpreted using the pseudo-quad model [3]. The most remarkable success is experimental observation of the returnable electron-phonon interaction by measuring the phonon spectra obtained with the synchrotron. Measurements of the temperature dependence of phonon modes made with exceptional thoroughness and accuracy (typical spectral frequency was 1 cm -1, and 2 cm -1 in some cases) revealed the discontinuity effect in the Cd 0,115 Hg 0,885 Te sample (see Fig. 1). It refers to how the frequency of HgTe-like and CdTe-like TO-phonon modes depends on temperature at the point of forbidden zero crossing (defined as g, the so-called Dirac point [4]). These discontinuities are resonant. Similarly, this phenomenon was observed in the Zn 0,1 Hg 0,9 Te sample, in which we also deal with the Dirac point. In this sample, the discontinuity of the dependence of phonon mode Figure 1. Plot of the frequency positions in the wave number vs temperature range of the HgTe-like and CdTe-like [4]. The most recent research made by the Polish-Italian team is concentrated on a general analysis of phonon spectra of mercury-containing compounds, for example Hg 1-x Zn x Te and Hg 1-x Cd x Te, taking into account their composition and temperature[7]. A generalization of the theoretical temperature shift of the phonon mode frequency as an analytic equation is derived. It includes both the anharmonic contribution and the electronphonon e-p interaction which is returnable in this case - the electron subsystem effect on the phonon one. Data show that our equation satisfactorily describes the temperature shift of both Hg Cd Te and Hg 0.90 Zn 0.10 Te containing Dirac point, although one of the two constants describing the anharmonic shift of the HgTe-like mode should be positive that is abnormal too. In the case of the Hg 0.80 Cd 0.20 Te and Hg Zn Te solid solutions, the role of the returnable e-p contribution is negligible, but a positive temperature shift for the HgTe-like modes occurs. This result does not explain the positive temperature shift of these modes merely by the contribution of the (e-p) interaction. Indeed, the relativistic contribution to the chemical bonds induces an abnormal temperature shift of the electron states in Hgbased semiconductors. The effect is expected since the Hg d spin-orbit split contribution to chemical bonds may lead to an abnormal temperature shift of the HgTe-like modes. [1] M. Cestelli Guidi et al., J. Opt. Soc. Am. A 22 (2005) [2] J. Cebulski et al., Phys. Stat. Sol. B 250 (2013) [3] J. Cebulski et al., Appl. Phys. Lett. 92 (2008) [4] E. M. Sheregii et al., Phys. Rev. Lett. 102 (2009) [5] E. M. Sheregii et al., Chin. J. Phys., 49 (2011) 214. [6] H. Kawamura et al., Solid State Commun. 14 (1974) 259. [7] M. Woźny et al., J. Appl. Phys. 117 (2015)

25 L-09 Thu , Status and science program of the European XFEL W. Gawelda* on behalf of the European XFEL GmbH European XFEL GmbH, Albert-Einstein-Ring 19, Hamburg, Germany Keywords: X-ray free-electron laser * The European X-Ray Free-Electron Laser (European XFEL) is currently under construction in the Hamburg metropole area, Germany. First electrons have been generated in the laser-driven injector and commissioning of the injector with beam will commence in autumn The production and the installation of the main superconducting accelerator, provided to a large extent through contributions by partners from a large number of countries, is in full swing. The 91 undulator segments to be installed for the various FEL sources have been produced, tested and are ready for installation. The challenging X-ray optics and diagnostics elements are under procurement and first components have been installed in the tunnels. At the same time, the design of the scientific instruments is largely complete and the installation has started. This important activity will continue until the start of operation. Further important developments concern the X-ray detectors, synchronized optical lasers, sample environments and the data acquisition and storage systems. By summer 2016 the accelerator construction and installation will be completed and commissioning with beam will be started at electron energy of 17.5 GeV. By the end of 2016 the electron beam and the undulators shall be ready for first generation of FEL radiation. In 2017 the commissioning of the electron beam, the undulator and FEL operation, and of the science instruments will continue. The three FEL sources and the six science instruments will be taken into operation in the sequence SASE1 SASE3 SASE2 over a period of about four to six months. In parallel, in 2017 first user experiments will be performed. Full performance of accelerator, FEL radiation and science instruments shall be reached in It is currently planned to increase the hours for accelerator operation dedicated to the user program from 1000 hrs in 2017, over 2000 hrs in 2018, to the final 4000 hrs in In the presentation the current layout of the facility and of the scientific instruments will be discussed. Major instrumentation efforts will be presented and an outlook to the commissioning of the facility and the initial science program will be provided. 15

26 L-10 Thu , Phase transitions in solids under irradiations with x-ray free electrons lasers characteristic time scales R. Sobierajski * Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, PL Warsaw, Poland, Keywords: free-electron laser * ryszard.sobierajski@ifpan.edu.pl The presentation is related to the development of presently most sophisticated 4th generation synchrotron radiation sources the short-wavelength free electron lasers (FELs). With the advent of the XFEL sources, a unique combination of radiation properties created new research possibilities. Radiation intensity produced in FELs, reaching the values of W/cm 2, exceeds by many orders of magnitude intensities available from other monochromatic X-ray sources, thus making it possible to excite a solid material through phase transition points up to, so called, warm dense matter condition. As typical pulse duration, on the order of femtoseconds, is shorter than most of the time constants related to structural transformations and to the energy transfer, it is possible to separate the processes from influence of radiation absorption during the pulse duration. Moreover, the photon energies, larger than value of energy gap in any material makes it possible to avoid nonlinearities in absorption what radically simplifies the modeling of the subsequent physical processes. Thus systematic studies of structural changes in materials, their electronic properties, as well as transition dynamics and energy transfer processes are possible. They can lead to better understanding of the material s properties like radiation hardness and to validation of the existing theoretical models of the energy transport in solids (see Figure 1). However, properties of the intense FEL beam create, apart from new experimental opportunities, the extreme demands to optical elements applied in the experimental equipment. The radiation load imposed on optical elements served for beam diagnostics, controlling and shaping can lead to their damage. Such materials are of special interest for studies of radiation hardness. It has been shown that optical coatings are destroyed by single FEL pulses if the beam s intensity/fluence exceeds a critical level single shot damage threshold [1-3]. At such a fluence the temperature of the material reaches phase transition point. Secondly, for a high repetition sources, like in the lithographic applications, the heat load on optics may reach kw level. This leads to the optics heating and its destruction, e.g. due to the enhanced atomic diffusivity in multilayer reflecting coating. Furthermore repeatable irradiations of optics may cause multi shot damage, e.g. related to thermal stresses. Moreover a rapid deposition of EUV pulse energy at the optics surface causes its hydrodynamical deformations what results in wavefront distortions for the proceeding pulses [4]. In my talk dominant processes that lead to the structural and electronic changes of solid materials under irradiations with intense femtosecond pulses of X-ray radiation will be presented. Characteristic time scales of these processes in a relation to the main materials nad radiation paremeters like pulse intensity, photon energy, radiation absorption depth, repetition rate of the source etc. will be discussed. Figure 1. Simulations of the heat diffusion in Si sample irradiated with 1 ps pulse of XUV radiation at normal incidence. Plot shows temperature color-map as a function of depth and time. Acknowledgments: This work has been partially supported by the Polish National Science Center (Grant No. DEC-2011/03/B/ST3/02453) [1] A. Aquila, R. Sobierajski et al., Appl. Phys. Lett. (2015) [2] J. Gaudin et al., Phys. Rev. B 86 (2012) [3] A. R. Khorsand, R. Sobierajski et al., Opt. Exp. 18 (2010) 700. [4] J. Gaudin et al., Opt. Exp. 19 (2011)

27 L-11 Thu , Magnetic impurities in the bulk and on the surface of 3D topological insulators probed using soft X-ray spectroscopy M. Waśniowska 1, M. Sikora 2,3 *, M. Dobrzański 2, I. Miotkowski 4, T. Eelbo 5, Z. Kąkol 2, A. Kozłowski 2 1 Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Germany 2 Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland 3 Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Krakow, Poland 4 Department of Physics, Purdue University,West Lafayette, Indiana, USA 5 Institute of Applied Physics,University of Hamburg, Germany Keywords: XAS, SXMCD, topological insulators, magnetic impurities, * marcin.sikora@agh.edu.pl Among the most important requirements for realization of versatile spintronic devices is a foundation of robust sources of the spin-polarized carriers. For semiconductors, this is achieved by means of an injection of spins directly from ferromagnetic material or by realizing magnetic semiconductors by means of diluted 3d transition metal (TM) impurities. The latter might also be realized in 3D-topological insulators (TI), in which the metallic surface states revealing the linear dispersion in a form of a Dirac cone, are robust against nonmagnetic impurities. In this contribution we present results of systematic investigations of electronic and magnetic properties of surface and bulk impurities into tetradymite semiconductors of Bi 2 Se 3-x Te x family by means of soft X-ray absorption and dichroism. We show how, depending on adatom/substrate type, different types of magnetic anisotropy either uniaxial out-of plane or basal ion-plane easy axis may be achieved [1-2]. Moreover, we discuss the intriguing oscillatory effects in electron yield detected XAS and its linear natural dichroism (XNLD) spectra, that are tentatively ascribed to X-ray induced plasmon excitations of well-defined frequency. By exploring evolution of electronic and magnetic properties of impurities we aim for revealing, how robust against magnetic impurities is the metallic state at the surface of canonical topological insulators, and how the extraordinary topology of electronic structure promotes the magnetic interactions. Based on the experience gained during realization of the project, we discuss the requirements for future undulator-based soft X-ray absorption and magnetic dichroism beamline at Solaris, that are essential for probing interactions and electronic structure of ultradiluted magnetic impurities in exotic systems. Acknowledgments: ESRF (Grenoble), UVSOR (Okazaki), and LNLS (Campinas) are acknowledged for providing beamtime. We are gratefull to J. C. Cesar, D. de Souza, K. Kummer, P. Kuświk, Y. Takagi, and F. Yakhou for their kind help during synchrotron experiments and sharing experience in operating SXMCD beamlines. MS acknowledges support from the grant of National Science Center of Poland (2014/14/E/ST3/00026). [1] T. Eelbo, M. Sikora, G. Bihlmayer et al., New J. Phys. 15 (2013) [2] T. Eelbo, M. Waśniowska, M. Sikora et al., Phys. Rev. B 89 (2014)

28 L-12 Thu , High Resolution Molecular Spectroscopy using synchrotron light source M. Kręglewski * Adam Mickiewicz University, Faculty of Chemistry, Poznań, Poland Keywords: HRMS, synchrotron IR source, nitromethane, * mkreg@amu.edu.p High Resolution Molecular Spectroscopy in gas phase is the main source of information about remote objects. High resolution means that vibrational molecular spectra are rotationally resolved. For floppy molecules the spectra can be more complex due to tunneling splitting. The heavier the molecule the smaller are its rotational constants and the spectra may be heavily congested. The successful recording of high resolution spectra requires that several exeperimental conditions are fulfilled: The gas pressure is low, usually below 1 mbar. The path length is long; the White-type multiple reflection cells are used. The source of IR radiation is stable in time and covers the whole spectral range. The noise level is small. For many years Fourier Transform Infrared Spectrometers are used as the main instrument to record high resolution spectra. The standard spectrometers have resolution of 0.02 cm -1. Typically, about hundred spectra are co-added to improve a signal/noise ratio. The analysis of high resolution spectra requires usually application of advanced software. Since high resolution spectroscopy brings important information about structure and dynamics of molecules in different vibrational states,there is an obvious expectation to apply this method to heavier molecules and molecules of the complex internal dynamics due to conformation changes. In such cases the experimental requirements become even more demanding, because of two main reasons: The density of lines is very high, often exceeding 400 lines/cm -1. The pressure broadening of individual lines must be minimized. The spectrometer able to record very dense and weak spectra must have following features: Stable source of radiation which allows for coaddition of many spectra. Source of high power which allows minimization of the gas pressure and study of weak transitions. Very long Maximal Optical Path Difference (MOPD) in Michelson interferometer. These conditions are best fulfilled by Fourier Transform Infrared spectrometers connected to synchrotron light sources. The power of a synchrotron light source in the infrared range is 20 times higher then that of a thermal Globar source. Thus, the aperture can be reduced from 1.5 to 0.9 mm leading to narrower lines. In FTIR spectrometer the resolution is determined through MOPD (Δν u =0.61/d MOPD ), which in standard spectrometer is equal to 2.5 m. In 8 existing synchrotron setups MOPD is extended to 9.8 m, and in Swiss Light Source up to 11.7 m. Thus, the best unapodized resolution at SLS is cm -1 [1]. This feature of the SLS spectrometer allow for analysis of fully resolved spectra of heavy molecules such as naphthalene and indole [2]. New spectrometer allows to study very week transitions in the spectral region which rarely visited using previous IR or mmw experimental techniques. Recently, at SLS the spectrum in the torsional region ( cm -1 ) of nitromethane was recorded for the first time. The torsional band is extremely weak, four order of magnitude weaker than other fundamental bands. The spectrum is being analyzed with a specialized software LWW (Loomis-Wood for Windows) developed in Poznań. First analysis reveals a number od Q branches. The assignment work is in progress. Figure 1. The Q-branch of nitromethane in the spectrum recorded at Swiss Light Source. [1] S. Albert, K. Keppler Albert, M. Quack in Handbook of High Resolution Spectroscopy, Vol. 2 (Eds.: M. Quack, F. Merkt, Wiley, Chichester, 2011, pp ). [2] S. Albert, K. Keppler Albert, P. Lerch, M. Quack, Faraday Discussions 150 (2011)

29 L-13 Thu , UARPES -Angle Resolved Photoelectron Spectroscopy beamline at National Synchrotron Radiation Centre SOLARIS J. J. Kolodziej 1,2 *, K. Szamota-Leandersson 2 1 Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Kraków, Poland 2 National Synchrotron Radiation Centre SOLARIS, Krakow, Poland Keywords: angle resolved photoelectron spectroscopy, synchrotron radiation, synchrotron facilities * jj.kolodziej@uj.edu.pl Angle Resolved Photoelectron Spectroscopy (ARPES) allows for measurements of fundamental quantities describing a photoelectron state in space, i.e. the energy (E) and the momentum (k). If a spin selector is used additionally, a complete set of quantum numbers for the electron may be obtained. Than, within a so called sudden approximation, the electron energy, momentum and spin measured over the sample surface may be related, to binding energy, quasimomentum, and spin, that the electron had in the solid before the photoelectric event took place. Thus the electronic band structure of the studied solid is obtained experimentally. Beside this simple picture ARPES gives also detailed insights into complex electron electron and electron lattice interactions in the solid. Many recent advances in materials science have been enabled by better understanding of the electronic structure of complex systems, gained due to ARPES studies. Examples include advances in fields such as high temperature superconductivity, topological insulators, graphene physics [1-15]. The importance of the ARPES technique for contemporary science and technology is widely recognized. Dedicated ARPES beamlines exist at almost all synchrotron radiation centers worldwide. Typically, for these beamlines, demanded beamtime many times surpasses the offered one. To meet the predicted demands a beamline dedicated for Angle Resolved Photoelectron Spectroscopy is constructed at SOLARIS synchrotron facility. It has been given an acronym UARPES (after Ultra ARPES). The UARPES beamline has been designed to have the following performance: energy range of ev; resolving power over the full energy range; photon flux on the sample 5x10 11 photons/s@20000 RP; available polarizations: vertical, horizontal, inclined, circular, elliptical; higher harmonics at the sample <1%; spot size on the sample 300 x 30 μm 2. Elliptically polarizing, APPLE-II type undulator is the UV radiation source. The undulator has quasiperiodic geometry for suppression of unwanted harmonics in its radiation spectrum. It is capable of both parallel and antiparallel modes of operation ensuring the full control over the light polarization. The beamline monochromator is combining normal (NIM) and grazing incidence (PGM) optics, similarly to recent implementation at SLS [12]. The NIM mode is indispensable for additional harmonics rejection, where they are particularly abundant, i.e. at the lowest photon energies. The NIM mode is designed to be used in the energy range 8 30 ev while the PGM mode in the energy range ev. The experimental endstation is composed of several ultrahigh vacuum chambers designed for sample processing and analysis, as well as devices for the sample storage and transfer. Cryogenic, 5-axes manipulator is capable of stabilizing the sample temperature in the range K, as well as of precise positioning of the sample surface for experiments. State-of-the-art electron energy spectrometer, having energetic resolution down to 1 mev, is capable of massively parallell recording of angle-resolved data spectroscopic data. Low energy electron diffractometer (LEED), with MCP image amplifier, is available for the sample positioning and surface structure studies. Processing devices allow for typical in situ sample surfrace preparation techniques such as sputter cleaning, thermal annealing, thin film growth, sample cleaving, surface reactions in the gas phase. Sample surface composition and crystallographic order may be monitored during preparation processess using combined LEED/AES device. [1] A. Damascelli et al., Rev. Mod. Phys. 75 (2003) 473. [2] J. C. Campuzano et al., Phys. of Supercond. 2 (2003)167. [3] M. A. Hossain et al., Nature 425 (2008) 527. [4] V. B. Zabolotnyy et al., Phys. Rev. B 76 (2007) [5] Y. Kamihara et al., J. Am. Chem. Soc. 130 (2008) [6] F. Bisti et al., Phys. Rev. B 91 (2015) [7] K. Schulte et al., Appl. Surf. Sci. 267 (2013) 74. [8] J. Maletz et al., Phys. Rev. B 89 (2014) [9] S. Ideta et al., Phys. Rev. 89 (2014) [10] A. A. Kordyuk, Low Temp. Phys. 40 (2014) 286. [11] D. Ootsuki et al., J. Phys. Soc. Jap. 83 (2014) [12] Y-J. Chang et al., Phys. Rev. Lett. 111 (2013) [13] H. M. Benia et al., Phys. Rev. B 91 (2015) [14] N. Xu et al., Phys., Rev. B 90 (2014) [15] M. Hashimoto et al., Nature Physics 10 (2014)

30 O-01 Tue , Momentum dependence of a Kondo resonance in Ce 2 Co 0.8 Si 3.2 P. Starowicz 1 *, R. Kurleto 1, J. Goraus 2, H. Schwab 3,4, M. Szlawska 5, F. Forster 3,4, A. Szytuła 1, I. Vobornik 6, D. Kaczorowski 5, F. Reinert 3,4 1 M. Smoluchowski Institute of Physics, Jagiellonian University, Lojasiewicza 11, Kraków, Poland 2 Institute of Physics, University of Silesia, Uniwersytecka 4, Katowice, Poland 3 Universität Würzburg, Experimentelle Physik VII, Am Hubland, D Würzburg, Germany 4 Karlsruher Institut für Technologie KIT, Gemeinschaftslabor für Nanoanalytik, D Karlsruhe, Germany 5 Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, Wrocław, Poland 6 CNR-IOM, TASC Laboratory, SS 14, km 163.5, I Trieste, Italy Keywords: Kondo resonance, angle-resolved photoemission spectroscopy, cerium intermetallics * pawel.starowicz@uj.edu.pl Ce 2 Co 0.8 Si 3.2 is a Kondo lattice system with the Kondo and coherence temperatures equal 50 K and 80 K, respectively. It crystallizes in a hexagonal structure, which is a derivative of the AlB 2 type. The system remains nonmagnetic down to 0.4 K and shows increased electronic specific heat, which amounts to C/T=200 mj/(mole Ce K 2 ) at low temperature (0.4 K). An evidence of Griffiths phases was found in Ce 2 Co 0.8 Si 3.2 below 10 K and is attributed to a disorder in the Co-Si sublattice. Band structure of Ce 2 Co 0.8 Si 3.2 was studied by means of angle-resolved photoemission spectroscopy (ARPES) at the APE beamline located at Elettra synchrotron [2]. The data were collected at temperature of 25 K with photon energies of 25 ev and 40 ev, which correspond, respectively to a low and high photoionization cross section for Ce 4f electrons. The studies with 40 ev revealed a Kondo peak (f 5/2 1 final state) and its spin-orbit partner (f 7/2 1 final state). Two bands crossing Fermi energy were found in the experiment, one of them has parabolic dispersion and is considered as a surface state. The second one forms an electron pocket in the Γ point. Band structure of stoichiometric Ce 2 CoSi 3 was calculated with full-potential local-orbital (FPLO) code. The dispersions from ARPES, which are attributed to bulk states were found in the calculations. The Kondo peak is nondispersing at T = 25 K but its intensity varies considerably with momentum. Its maximum of the intensity corresponds to a Fermi vector of the band found in the FPLO calculations, a dispersion of which was not revealed by ARPES. For the other Fermi vectors Kondo resonance is of moderate or lower intensity. The variation of a Kondo peak intensity along a Fermi surface is in line with the theory predicting a strong anisotropy of hybridization between f-electrons and conduction band (V cf ) [3-5]. Acknowledgments: This work has been supported by the Ministry of Science and Higher Education in Poland within the Grant no. N N A part of the measurements was carried out with the equipment purchased thanks to the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG /08). [1] M. Szlawska, D. Kaczorowski, J. Phys.: Condens. Matter 26 (2014) [2] P. Starowicz, R. Kurleto, J. Goraus, H. Schwab, M. Szlawska, F. Forster, A. Szytuła, I. Vobornik, D. Kaczorowski, F. Reinert, Phys. Rev. B 89 (2014) [3] H. Weber, M. Vojta, Phys. Rev. B 77 (2008) [4] J. H. Shim, K. Haule, G. Kotliar, Science 318 (2007) [5] P. Ghaemi, T. Senthil, P. Coleman, Phys. Rev. B 77 (2008)

31 O-02 Tue , Structural evolution of (Ga,Mn)As thin film during medium temperature post growth annealing manifested by XAS Y. Melikhov 1, J. Sadowski 2, P. Konstantynov 1, M. Chernyshova 3, J. Domagala 1, T. Wojciechowski 1, I. N. Demchenko 1 1 Institute of Physics, Polish Academy of Sciences, Warsaw, Poland 2 MAX IV Laboratoriet, Lund, Sweden 3 Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland Keywords: (Ga,Mn)As, DMS, annealing, DFT, multiplescattering, EXAFS, XANES * melikhov@ifpan.edu.pl An extensive research is currently being conducted to develop a diluted magnetic semiconductor (DMS) with room temperature ferromagnetism and proper transport properties, qualities desired for future spintronics devices. (Ga,Mn)As is the most studied DMS material and with the optimized MBE growth and post growth annealing procedures the Curie temperature, T C, as high as about 200 K has been achived, see, e.g., [1] where the results of different heat-treatment conditions are presented. A comprehensive understanding of the microstructure evolution on transformation processes (including formation and migration of point defects) which occur in (Ga,Mn)As during growth and post growth annealing could potentially lead to a further progress in reaching higher T C. The goal of this work is to add to this understanding by checking the effectiveness of X-ray absorption spectroscopy as a probe of structural evolution of (Ga,Mn)As after medium temperature post growth annealing (up to 450 o C). The (Ga,Mn)As layer was grown in a SVTA MBE system [2] on GaAs (100) substrate with thin AlAs buffer layer. An amorphous As capping layer was deposited on (Ga,Mn)As at the end. After removing from the MBE setup, the film was cleaved into three pieces: one piece was left intact and the other two were annealed at temperatures 350 o C and 450 o C. After conventional initial analysis, the (Ga,Mn)As layer was separated from the GaAs substrate on all samples by chemical etching, a so-called lift-off procedure [3], in order to avoid disturbance of X-ray absorption measurements by Bragg scattering of the bulk GaAs substrate at defined values of energy of incident beam. The content of Mn in the Ga 1-x Mn x As layer was estimated to be ~1 at.% by Energy-dispersive X-ray spectroscopy (EDX) using Auriga 40 FIB-SEM workstation. High resolution diffraction studies were performed using a Philips X Pert-MRD diffractometer equipped with a parabolic X-ray mirror, a four-bounce Ga 220 monochromator at the incident beam, and a three-bounce Ge analyzer at the diffracted beam. The qualitative analysis of ω/2θ scans obtained for the symmetric (004) reflection for the annealed samples allows to manifest the structural reorganization in (Ga,Mn)As film. It is assumed that initially Mn atoms 21 form N-mers which is followed by transition to Mnrich areas in GaAs matrix, like inclusions. In order to determine the electronic and atomic structure around Mn atoms the XAFS spectra at the K- edge of Mn were gathered at the BL22 CLÆSS beamline at ALBA synchrotron light facility [4]. Figure 1 presents normalized XANES spectra around Mn K edge and an inset shows modulus of Fourier transforms, FT(R), of the EXAFS function for the samples. The quantitative analysis of XANES and EXAFS of the as-grown sample indicates that Mn atoms most likely substitute Ga atoms in the GaAs matrix. For the annealed samples, a dramatic decrease of the amplitude of FT(R) function can be satisfactory explained by changing in either of these highly correlated parameters: an increase in Debye-Waller factor (accounting for structural and thermal disorder) will result to the same effect as a decrease in number of the atoms in corresponding coordination shell, e.g. by forming As vacancy/ies around Mn atom in the 1 st shell. To test the latter hypothesis a possibility to form a specific type of point defect including, for instance, V As, Mn Ga, and their combinations, was estimated by calculating their formation energies using Quantum Espresso DFT code. The structures with the defects with the lowest formation energies were used by FEFF8 multiple-scattering code to calculate theoretical XANES spectra. It was found that reasonable combination of several theoretical spectra provide good qualitative agreement with the experimental ones. In addition, as the hypothesis directly implies the existence of vacancies in (Ga,Mn)As, positron annihilation measurements are planned to estimate type and amount of vacancies in the samples allowing to correlate them with the observed by XAFS effects. Intesity [arb. units] Mn K edge XANES: as grown annealed at ( o C): Ga 1-x Mn x As x ~ 1 at.% (R) [Å -2 ] R [Å] Photon energy [ev] Figure 1. Normalized Mn K-edge XANES spectra of the (Ga,Mn)As layers. The inset shows Fourier transforms of the k 1 -weighted Mn K-edge EXAFS χ function. Acknowledgments: This work was supported by the Baltic Science Link project coordinated by the Swedish Research Council, EAgLE project (Project Number: ), CALIPSO program and PL-Grid and ICM infrastructures. [1] M. Wang et al., Appl. Phys. Lett. 93 (2008) [2] J. Sadowski, J. Z. Domagala, chapter 2 in Advanced Functional materials: A perspective from theory to experiment (Eds. B. Sanyal and O. Eriksson; Elsevier, 2012). [3] S. Decoster et al., J. Synchrotron Rad. 20 (2013) 426. [4] ALBA light source, Spain,

32 O-03 Tue , Fabrication and characterization of multilayer solar cells M. Pławecki the ZnO/Cu 2 O may be produced at ambient conditions. ZnO has been a preferred candidate of window layer of solar cell because of its wide and direct band gap of 3.37 ev at room temperature, good diode characteristics in the dark especially its very high photocurrent [7]. Institute of Materials Science, University of Silesia, 75 Pułku Piechoty 1A, Chorzów.Poland Keywords: zinc oxide, cuprous oxide, solar cell * mplawecki@us.edu.pl The solar cells based on copper oxide and zinc oxide are a promising alternative to conventional silicon cells because of the relatively low cost of production and the theoretical efficiency of approx. 16% [1-3]. First of all, this paper focuses on the characteristics of the ZnO layer - n-type, and Cu 2 O/CuO - p-type semiconductors prepared by electrodeposition, which allows to create transparent semiconductor layers with good optoelectronic properties [4]. Secondly, fabrication of perovskites layers which acts as light absorber [5]. Perovskites having the composition of CH 3 NH 3 PbX 3 (X = I, Br) are examined as an attractive absorbing materials for use in low cost solar cells with high efficiency. For about five years, there has been an increase in energy conversion efficiency of these materials, which shows remarkable potential of their usage. However, in most devices, including thin-film simplest planar structure identifying the basic working mechanisms, which are still being debated, will be crucial to design the optimum device configuration and maximize solar cell efficiencies. Combining different methods of production with relatively low cost such as spin coating for perovskite and electrolytic deposition for metal oxides semiconductors provides possibility to create multifunctional layers and improve efficiency and reduce cost of solar cells. Cu 2 O layers were prepared on pre-cleaned Fluorine doped Tin Oxide (FTO) glass plate by electro deposition using platinum as counter electrode, ZnO layers were galvanostatically electrodoposited and CH 3 NH 3 PbX 3 was spin-coated under 100 C. Cuprous (I) oxide (Cu 2 O) semiconductors are a promising candidates of an all functional-oxide solar cell material because of its photo electronic properties such as proper energy band gap of 2.1 ev, environmentally friendly properties such as non-toxicity and low material cost [1,2]. It was proven that a solar cell devices based on. Figure 1. Concept of solar cell with perovskite absorber. All the crystalline components in the Cu 2 O and ZnO thin films were investigated by XRD, diffraction peaks corresponding to Cu 2 O and ZnO were observed in thin films, which consisted of cupric phase with monoclinic system. It was shown that the solar cell devices have the structures of crys-cu(001)/ p poly-cu 2 O/Ag and poly- Cu/ p -poly-cu 2 O/Ag, which convert solar energy into electrical energy. Additianal the layers deposited on FTO were studied by XPS measurements. The core levels S 2p, Cu 2 p, O 1s, C 1s, Zn 2p spectra and the Cu Auger spectrum were measured. During formation of the layer on the surface of FTO all processes proceed in an open medium; therefore, it is not possible to avoid ambient effects. Since the surface of this layer is active, it adsorbs oxygen, water, and other contaminants. Therefore the surface of the layer can differ from the macrostructure and chemical composition of the entire layer. Finally the analysis of the current voltage characteristics was applied to determine the values of electrical parameters of the solar cells [6,7]. [1] Kazuya Fujimoto, Takeo Oku et al., Journal of Physics: Conference Series 433 (2013) [2] S Noda, H Shima et al., Journal of Physics: Conference Series 433 (2013) [3] V. Popescu, et al., Phys. Rev. B 78 (2008) [4] O. Breitenstein, Electronics Review 21 (2013) 259. [5] M. M. Lee et al., Science 338 (2012) 643. [6] A. Boudghene Stambouli, E. Traversa, Renewable and Sustainable Energy Reviews 6 (2002) 297. [7] C. H. Hsu, L. C. Chen, Y. F. Lin, Materials 6 (2013)

33 O-04 Tue , Application of X-ray absorption and resonant photoemission spectroscopy to study electronic states of iron through 3p-3d transition for SrTiO 3 :Fe epitaxial film J. Kubacki 1,2 *, D. Kajewski 2, A. Koehl 3, Ch. Lenser 3, R. Ditmann 3, J. Szade 1,2 1 Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, Chorzow, Poland 2 A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, Katowice, Poland 3 Peter Grünberg Institut, JARA-FIT, Forschungszentrum Jülich, Jülich, Germany Keywords: X-ray absorption, resonant photoemission, strontium titaniate, doping by iron * jerzy.kubacki@us.edu.pl The strontium titanate STO is promising material for electronic application. The electrical properties of this material can be tuned by iron doping. The synchrotron radiation was used to study of SrTiO 3 doped by 2% of iron thin film. As was shown in our earlier work the oxidation states of iron in the STO:Fe thin films is in a mixture of Fe2+ and Fe3+ states [1]. In order to confirmation and distinguish oxidation states of iron at sub-surface layer of the film we performed X-ray absorption study in range of the Fe M-edge threshold. The pure SrTiO 3 is an isolator with a energy gap of 3.6 ev. The valence band of SrTiO 3 contains mainly O2p-Ti3d hybridized states. The influence of Fe3d electrons on the density of states in the energy gap was study by resonant photoemission in range Fe3p-3d resonance. Measured spectra are compared with the results obtained for Fe2p-3d resonance [2]. The X-ray absorption spectra obtained for the Fe M-edge contains two main peaks at 53 ev and 59.6 ev of photon energy. In order to analysis of the shape obtained curve we performed atomic multiplet calculation of Fe3p absorption spectra using the CTM4XAS program [3]. To verify obtained result also photoemission Fe3p spectra was measured and compared with calculation. In figure 1a only a shape of the first peak of absorption was showed. The valence band spectra, presented in figure 1b, were measured in the binding energy range from 3 to 13 ev. We explored the photon energy range across the Fe3p-3d photoionization threshold (47 ev 54 ev). Two features A and B are clearly visible at energy of about 4 ev and 6 ev, respectively. The relative intensity of observed maxima is changed with energy of photon. The intensity of B feature increases for the energy of photon higher than h =53 ev. The valence band spectra measured -in and -off resonance was presented in figure 2. Small changes at localization of B feature are visible. Intensity (a.u.) Normalized Intensity Photon Energy (ev) Figure 1. a) Fe M-edge XAS spectra recorded for Fe doped STO films obtained in AEY mode. b) Photoemission spectra of the valence band region measured in range of photon energy corresponding to Fe3p-3d photoionization threshold. Normalized Intensity a) b) ResPES 10 h = 47eV 10 A B 1:E=47eV 6:E=62eV SrTiO 3 :2%Fe Binding Energy (ev) Figure 2. The details of valence band spectra measured at energy of photon in and off resonance. The mixed valence of iron was discussed based on the X-ray absorption spectroscopy and atomic multiplet calculation. The influence of Fe 3d state on valence band STO:Fe film was study by resonant photoemission. Small difference in shape of valence band was detected in resonance. Acknowledgments: This work was supported by NCBiR/ERA-NET-MATERA/3/2009 project h = 62 ev h = 53eV 5 0 Binding Energy (ev) [1] A. Koehl, Phys. Chem. Chem. Phys. 15 (2014) [2] J. Szade et. al., in preparation [3] E. Stavitski, F. M. F. de Groot, Micron 41 (2010)

34 O-05 Extended abstract Tue , Laboratory sources of soft X-rays and extreme ultraviolet (EUV) based on laser plasmas produced with a gas puff target H. Fiedorowicz*, A. Bartnik, P. W. Wachulak, R. Jarocki, J. Kostecki, M. Szczurek, D. Adjei, I. U. Ahad, M. G. Ayele, T. Fok, A. Szczurek, A. Torrisi, Ł. Węgrzyński 1 Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, Warsaw Keywords: lasers, laser plasmas, laser plasma sources * hfiedorowicz@wat.edu.pl Electromagnetic radiation in the soft X-ray and extreme ultraviolet (EUV) wavelength ranges can be produced in a high-temperature plasma generated by interaction of high power laser pulses with matter [1-3]. It was demonstrated that laser plasma soft X-ray and EUV sources could be useful in various applications in physics, material science, biomedicine, and technology. However, conventional laser plasma sources based on a solid target have debris production problem. We have demonstrated that using a double-stream puff target, instead of a solid target, it is possible to develop highly efficient and debris-free laser plasma soft X-ray and EUV sources [4-5]. The target is formed by injection of high-z gas (xenon, krypton, argon, etc.) into a hollow stream of low-z gas (hydrogen and helium) using a double nozzle. The nozzle setup consists of a central nozzle in a form of a circular orifice, surrounded by an outer nozzle in the form of a ring. The nozzle is supplied with gases from two electromagnetic valves mounted in a common body. Strong soft X-ray and EUV emissions from the double-stream gas puff targets, exceeding the emissions from solid targets, have been demonstrated [6]. In the paper laser plasma sources of soft X-rays and EUV based on a gas puff target, developed for various applications, including metrology and microscopy, photo-etching and processing of materials, surface modification, radiography and tomography, radiobiology and material damage, photoionization of gases and cold plasma formation, are presented. The gas puff target approach was used for developing a compact laser plasma EUV source for metrology applications [7]. The xenon target was irradiated with 4 ns/0.5 J pulses produced with repetition rate of 10 Hz from a commercial Nd:YAG laser. Conversion efficiency of the laser energy into the EUV energy at 13.5 nm wavelength of about 2 % was measured in 7 % wavelength band, corresponding to about 0.5 % in 2 % band [8]. The source has been used in the measurements of optical characteristics of Mo/Si multilayer mirrors [9]. High-brightness soft X-ray source based on the gas puff target driven with the PALS laser facility [10, 11] has been used for the first time for processing materials. Direct photo-etching of inorganic (silicon) and organic (polymers) materials with nanosecond pulses of soft X-ray and EUV radiation was demonstrated [12, 13]. 24 Efficient processing of organic polymers (PMMA and PTFE) has been also demonstrated with the compact EUV source for metrology, operating at 10 Hz [14] and strong temperature effect on soft X-ray photo-etching of PTFE was shown [15]. The same source equipped with a multi-foil optic collector [16] has been used to study the EUV emission from solids irradiated with intense EUV pulses [17]. A new technique for detection of surface changes of materials, utilizing scattered or luminescent EUV radiation, was proposed [18]. The use of a grazing incidence axisymmetrical ellipsoidal mirror as a collector strongly increased the EUV fluence on irradiated samples up to 100 mj/cm 2 [19]. This made possible to increase dramatically the EUV ablation rates and improve micromachining of polymers. Efficient processing of non-organic materials (SI, Ge, NaCl, and CaF 2 ) has been also demonstrated [20]. Modification of polymer surfaces by creation of characteristic micro- and nanostructures was observed in case of irradiation with EUV pulses at relatively low fluence (<10 mj/cm 2 ) [15, 21-25]. It was found that such EUV patterning of surfaces can be useful for biocompatibility control of polymers [26]. These studies resulted in development of the source dedicated for EUV processing of materials [27]. Laser plasma EUV source for processing is composed of a vacuum chamber in a form of a vertical column mounted onto a cubical base, housing a compact commercial Nd:YAG laser system (EKSPLA) generating 4 ns laser pulses with energy up to 800 mj and vacuum pumping system. The source chamber is composed of three sections. Each section is pumped separately by oilfree vacuum pumps (differential pumping). In the first upmost section of the chamber the electromagnetic valve to produce a gas puff target and the laser beam focusing system are placed. The valve is mounted using the x-y-z translation stages, allowing placing the gas puff target in the required position with accuracy of about 10 m. The gas puff targets are formed by pulsed injection of working gas (krypton, xenon or krypton/xenon mixture) into a stream of helium, using an electromagnetic valve system with a double-nozzle setup. The repetition rate of the system is determined by the repetition rate of the laser (10 Hz). The source is equipped with a grazing incidence axisymmetrical ellipsoidal mirror (RITE), to focus the EUV radiation. The mirror is mounted in the second, central section of the vacuum chamber. It makes possible to focus the EUV radiation onto a polymer sample mounted in the third section of the chamber, evacuated to high-vacuum. The EUV radiation is focused to a spot of about 1 mm in diameter with fluence up to 100 mj/cm 2 for the xenon gas puff target [28]. The source has been used for EUV micromachining of poly(vinylidene fluoride) (PVDF). PVDF is an important fluoropolymer because of its piezoelectric, pyroelectric and ferroelectric properties. It is also known to have an extremely high chemical stability and electrical resistivity. Micro- or even nanopatterning of PVDF is highly desirable for applications in multifunctional and integrated devices. Many works have been performed on surface processing of PVDF using ion beams, synchrotron X-ray and UV laser radiation,

35 however, irradiation of PVDF with these sources resulted in strong modification of the molecular structure in a near-surface layer of the polymer. Using the laser plasma EUV source dedicated for processing polymers we have demonstrated for the first time efficient micromachining of PVDF without changing the chemical structure of the unprocessed material [29]. PVDF foils of 50 m thickness (Goodfellow) were irradiated with the EUV radiation through a contact metal mask with square orifices m 2. Micro holes etched through the foils have been obtained as a result of 1 min irradiation at 10 Hz repetition rate. Investigation of the ablation products with QMS demonstrated a good agreement between the stoichiometric composition of PVDF molecules in the ablated and bulk polymer. XPS spectra, acquired for the polymer after ablation, are almost identical to the spectrum of pristine PVDF, indicating preservation of the chemical structure of the remaining material. However, XPS measurements performed on the polymer irradiated with low fluence (<10 mj/cm 2 ) indicated strong chemical modification in the near-surface layer. In this case defluorination and thus carbon enrichment in the surface material was revealed [29]. We have demonstrated in our previous works that EUV radiation can be used for surface modification of polymers for biocompatibility control [26, 30]. Surface modification of PTFE, PVDF and PC polymers for biocompatibility control has been studied using the laserplasma EUV source. Modified surfaces were characterized by SEM and AFM. Up to several hundred nanometers high wall-type micro- and nanostructures were formed [31]. Simultaneous treatment of polymer surface by EUV radiation and ionized nitrogen injected in the interaction region has been studied [32]. Chemical analysis by XPS revealed decreased oxygen contents in PC samples and nitrogen enrichment in PTFE [31, 33]. Exclusion of oxygen from polar groups leads to a polymer with increased hydrophobicity that was confirmed by contact angle measurements. Biocompatibility tests of PTFE and PVF samples modified with the EUV photons and seeded with fibroblasts have shown strong cells adhesion to polymer surfaces [34]. The compact laser plasma EUV source, additionally equipped with an ellipsoidal mirror with the Mo/Si coating and operating with the argon gas puff target, allowed producing quasi-monochromatic EUV radiation at 13.8 nm wavelengths [35]. This source has been successfully used for EUV nanoimaging with the spatial resolution down to 50 nm, proving possibility to develop a compact, desk-top EUV imaging tool [36-38]. The tool was also used for EUV imaging of nanostructures [39], crystalline thin films and nanofibers [40]. The compact EUV source has been also used for pulsed radiography and tomography of the gas puff targets. The beam of EUV radiation for backlighting of a target under study was produced by spectral selection of emission from xenon plasma using a Mo/Si multilayer mirror. To eliminate the visible light from the plasma a 200 nm thick Zr filter deposited on a 200 nm thick Si 3 N 4 membrane was used. In this way quasimonochromatic radiation at 13.5 nm wavelength with the bandwidth of about 1nm was obtained. The EUV shadowgrams of the targets were registered with the use of the back-illuminated CCD camera (Reflex), equipped with a pixels CCD chip. The EUV radiography setup was used for characterization of the multi-jet gas puff targets with modulated gas density for high-order harmonic generation (HHG) experiments [41] produced using the nozzles in a form of linear array of 5, 7 or 9 orifices. 2-D gas density map for the target produced using the nozzle with 7 orifices at the backing pressure of 4 bar and corresponding gas density profiles for various distances are presented in [42]. The radiography setup with the laser plasma EUV source has been also used for characterization of the dual-gas multi-jet gas puff target [43], the pulsed gas cells [44] developed for HHG experiments and the elongated plasma channels [45]. The same setup was used for the EUV tomography of the multi-jet gas puff targets. In this case the gas puff valve was mounted on top of a rotation stage to ensure 2 rotation of the nozzles while acquiring projections. The set of 900 EUV projections was used for tomographic reconstruction. The 3-D image of the multijet gas puff target has been obtained [46, 47]. A new technique for 3-D tomographic reconstruction of low density objects with the use of a compact laser plasma EUV source was demonstrated. Laser plasma soft X-ray sources operating in the water window wavelength range between 2.3 nm and 4.4 nm are used for microscopy of live biological objects. It was shown that the laser plasma source with argon or nitrogen gas puff targets is an efficient source of radiation in this range [48]. This source has been used for development of a compact, desk-top soft X-ray microscope, based on a laser plasma source, operating in the water window range. The microscope was equipped with an ellipsoidal grazing incidence mirror coated with nickel as a condenser to focus soft X-ray radiation from the plasma onto a sample [49]. A Wolter type grazing incidence hyperboloid/ellipsoid axisymmetrical mirror was used as an objective to form a magnified image onto a CCD camera. The first soft X-ray microscopy images in the water window spectral range of biological samples (onion skin cells) with sub-micron spatial resolution have been obtained [50]. Much better resolution was obtained using a Fresnel zone plate as a microscope objective. The Fresnel zone plate was 250 m in diameter, with the outer zone width of 30 nm and the focal length at 2.88 nm f = 2.6 mm. Soft X-ray microscopy images of the test object (the TEM mesh) could be registered in 10 s exposure time (100 pulses). The spatial rsolution assessed by the knife edge test was equal to 60 nm. The resolution for a singleshot exposure was about 240 nm [51]. The microscope has been used for imaging of biological samples. Soft X-ray images of thin layers of saccharose (160 nm) and plasmid DNA deposited on the Si 3 N 4 membrane have been obtained in 20 s and 50 s exposition times, respectively [51]. 25

36 The laser plasma soft X-ray source with an argon gas puff target irradiated with the 4 ns/0.8 J/10 Hz Nd:YAG laser was developed for application in radiobiology experiments [52]. The source delivers approximately photons/4π in the wavelength range of about nm. The low penetration depth of this radiation in biological samples and pulsed character of the source lead to high local dose loads and dose rates, respectively. The design of the source allows samples to be irradiated both in vacuum and in He-environment. Doses in a single pulse of soft X-rays of about 300 Gy for irradiation in vacuum and about 20 Gy for the He-environment irradiation were measured. Initial irradiation experiments carried out with plasmid DNA demonstrated that the source can be used in systematic studies of soft X-ray radiation damage to biomacromolecular samples and other biological specimen [53]. The source has been also used for the soft X-ray contact microscopy experiments [54]. The laser plasma EUV source for processing of materials has been also used in the first experiments on EUV photoionization of atomic and molecular gases. Gases were injected into the focus of the EUV beam using an additional gas nozzle mounted in the third section of the source chamber. Formation of lowtemperature photo-ionized neon plasmas induced by nanosecond EUV pulses from the laser plasma source and by femtosecond EUV pulses from the FLASH free electron laser was studied [55]. Luminescence of helium and neon gases induced by the EUV pulses was measured [56] and significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas have been detected [57]. Spectral investigations in the EUV/VUV region of photoionized plasmas induced in atomic and molecular gases using nanosecond EUV pulses were performed [58]. EUV photoionization of gases and formation of lowtemperature plasmas have been also studied using more energetic EUV pulses generated as a result of irradiation of the gas puff target with laser pulses with time duration from 1 ns to 10 ns and energies from up to 10 J at 10 Hz repetition rate produced from the Nd:YAG laser system (EKSPLA) [59]. These preliminary investigations have shown applicability of compact laser plasma EUV sources for research in a new field of EUV-induced plasmas. Acknowledgments: This work was supported by the EC s 7. Framework Program (LASERLAB-EUROPE II - grant agreement n and LASERLAB-EUROPE III - grant agreement n , and the Erasmus Mundus Joint Doctorate programme EXTATIC), the National Centre for Science (award number DEC-2011/03/D/ST2/00296), and the National Centre for Research and Development Lider Programme, (award number LIDER/004/410/L-4/12/NCBR/2013). [1] I.C.E. Turcu and J.B. Dance, X-rays from laser plasmas: Generation and applications (Wiley 1998). [2] D.T. Attwood, Soft X-rays and extreme ultraviolet radiation: Principles and applications (Cambridge University Press 1999). [3] V. Bakshi, EUV sources for lithography (SPIE Press Book 2006). [4] H. Fiedorowicz et al., Appl. Phys. B 70 (2000) 305. [5] H. Fiedorowicz et al., Opt. Commun.184 (2000) 161. [6] H. Fiedorowicz, Laser Part. Beams 23 (2005) 365. [7] H. Fiedorowicz et al., J. Alloys Compd. 401 (2005) 99. [8] R. Rakowski et al., Appl. Phys. B 101 (2010) 772. [9] R. Rakowski et al., Opt. Appl. 36 (2006) 593. [10] K. Jungwirth et al., Phys. Plasmas 8 (2001) [11] H. Fiedorowicz et al., J. Alloys Compd. 362 (2004) 67. [12] L. Juha et al., Nucl. Instr. Meth. A 507 (2003) 577. [13] H. Fiedorowicz et al., Microel. Eng (2004) 336. [14] A. Bartnik et al., Microel. Eng (2005) 452. [15] A. Bartnik et al. Appl. Phys B 82 (2006) 529. [16] L. Sveda et al., Phys. Scr. T123 (2006) 131. [17] A. Bartnik et al., Appl. 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37 O-06 Wed , Single-crystal X-ray diffraction at extreme conditions D. Paliwoda*, M. Hanfland European Synchrotron Radiation Facility, B.P.220, F Grenoble Cedex, France Keywords: high pressure single crystal diffraction, synchrotron radiation. * Pressure is one of basic thermodynamic parameters, however its effect on chemical reactions, properties of materials and their structure remains relatively poorly understood, mainly due to the lack of experimental data. This deficiency of high-pressure information, compared to the vast amount of low- and high-temperature data, is due to the technical requirements of high-pressure experiments. They could be conducted only in strong vessels with thick walls, capable of withstanding high pressure, but obscuring access to the sample. The breakthrough in the high-pressure methods was the invention of the diamond-anvil cell, DAC [1]. Its design evolved in the second half of XX th century and finally made the DAC a powerful tool for in situ spectroscopic and diffraction investigations. High pressure crystallography has become an efficient technique for crystal structure determinations and for monitoring phase transitions [2,3]. The diamondanvil cell can be nowadays routinely applied in laboratories and dedicated beamlines of synchrotron and neutron facilities. Synchrotrons provided new quality in X-ray diffraction and particularly in these experiments where very high intensity of the radiation is needed. It can be especially advantageous in high pressure crystallography, where the size of the sample is reverse to the attainable pressure. The High Pressure Beamline ID09A at the European Synchrotron Radiation Facility is dedicated to the determination of structural properties of solids at high pressure using angle-dispersive-diffraction with diamond anvil cells. It offers monochromatic diffraction with large area detectors and provides beam seizes down to 10 x 10 µm at very high photon fluxes. High-pressure powder and single crystal data can be collected from ambient pressure to approximately 200 GPa, as well as at low and high temperatures. Several examples illustrating high pressure crystallographic studies and the research potential of ID09A are going to be presented. Figure 1. Membrane Diamond Anvil Cell (MDAC). [1] C. E. Weir, E. R. Lippincott, A. Van Valkenburg, E. N., Bunting, J. Res, Natl. Bur. Stand. 63A (1959) 55. [2] T. Boffa Ballaran, A. Kurnosov, D. Trots, High Pressure Research, 33 (2013) 453. [3] M. I. McMahon, High Pressure Crystallography (in Advanced X-ray Crystallography, Springer-Verlag Berlin Heidelberg 2012). 27

38 O-07 Wed , High-brilliance X-ray sources: a bright future for life science studies J. B. Pełka* Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, Warsaw, Poland Keywords: synchrotron radiation, free electron laser, life sciences * pelkay@ifpan.edu.pl More than twenty years ago, a wide access to 3 rd generation synchrotron radiation (SR) sources has brought an accelerated growth in studies of a condensed matter. Unique properties of SR together with countless improvements both in the experimental and computational techniques have also opened up new exciting era, especially in research of the biological structures and processes. A variety of methods employed to study biological matter on the levels from molecules through cells and tissues up to whole organisms, like X-ray crystallography, spectroscopies in a broad range of wavelengths from IR up to hard X-rays, a number of imaging techniques, and many other, have led to a substantial progress in the life science and related fields. The history repeats over the last decade, due to a rapid development of the short-wavelength Free Electron Lasers (FELs), new 4 th generation SR sources. They can produce a fully tunable monochromatic radiation, including hard X-rays, in ultrafast femtosecond pulses with a peak power up to several GW. FELs break fundamental barriers that limit all other known X-ray sources. This means new marvelous qualities in probing the secrets of life with unprecedented femtosecond temporal and atomic spatial resolution. With FELs, it is possible to study even single macromolecules using enormously large, damaging irradiation doses and acquire structural information before the object is damaged. In this way one can explore both crystals and small nanocrystals and noncrystalline materials. This talk is aimed at showing, in a short trip across fascinating areas of high-brilliance X-ray sources, how plainly is emerging the brightest ever future for experimental methods. The perspectives emerging from having to be opened soon the first Polish synchrotron, SOLARIS, as well as the access to the EU-XFEL facility in Hamburg, the project developed with participation of Poland will be also mentioned. O-08 Wed , SAXS studies of selected flexible proteins or proteins of modular structure M. Kozak*, Z. Pietralik, M, Taube 1 Department of MaclomolecularPhysics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland Keywords: synchrotron radiation, small angle X-ray scattering, disordered proteins, modular structure * mkozak@amu.edu.pl Small angle scattering of synchrotron radiation (SR- SAXS) is a technique, which is suitable to the study of difficult biomacromolecules, and especially the low resolution structure in solution of the proteins possessing the flexible or modular structure. Due to the flexibility of the conformation of these macromolecules, is very difficult (or nearly impossible) to obtain their atomic structures based on the classic methods of protein crystallography. On the other hand, these proteins often play important physiological functions in which a flexible conformation of the protein molecule is crucial for the its function (in regulation, signaling and control pathways) [1]. The physiological function of flexible proteins often is complementary to function played by other ordered protein molecules or protein domains [2,3]. Therefore is very important to have in our disposal a routine method dedicated to the determination of flexible structures in solution. SAXS technique also offers also a substantial support in the prediction and modelling of protein structure by the use of bioinformatics. Low resolution structural protein models in solution, obtained by SAXS, can be used as templates (molecular envelopes) for docking of bioinformatics models [4]. As a result, the full molecular structures, even large proteins or protein complexes, can be determined [5]. In recent years, SAXS is also used in other applications, including also the use of low resolution models to verify NMR structures, or even in supplementation the NMR data [6]. During the lecture will be presented the applications of SR-SAXS technique in the study of selected disordered protein systems, modular proteins, protein complexes, denaturation processes as well as the conformational dynamics of macromolecules in solution. Special attention will be paid on proteins from plant innate defence systems [7], regulatory proteins and on the conformational dynamics of proteins involved in neurodegenerative diseases [8]. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC-2012/06/M/ST4/ [1] V. N. Uversky, Biochimica et Biophysica Acta 1834 (2013)

39 [2] A. K. Dunker, J. D. Lawson, C. J. Brown, R. M. Williams, P. Romero, J. S. Oh, C. J. Oldfield, A. M. Campen, C. M. Ratliff, K. W. Hipps, J. Ausio, M. S. Nissen, R. Reeves, C. Kang, C. R. Kissinger, R. W. Bailey, M. D. Griswold, W. Chiu, E. C. Garner, Z. Obradovic, J. Mol. Graph. Model. 19 (2001) 26. [3] H. J. Dyson. P. E. Wright, Nature Reviews Molecular Cell Biology 6(3) (2005) 197. [4] D. Schneidman-Duhovny, A. Rossi, A. Avila-Sakar, S. Joong Kim, J. Velázquez-Muriel, P. Strop, H. Liang, K. A. Krukenberg, M. Liao, H. Min Kim, S. Sobhanifar, V. Dötsch, A. Rajpal, J. Pons, D. A. Agard, Y. Cheng, A. Sali, Bioinformatics 28 (2012) [5] H. D. Mertens, D. I. Svergun, J Struct Biol. 172 (2010) 128. [6] M. Kozak, A. Lewandowska, S. Ołdziej, S. Rodziewicz- Motowidło, A. Liwo. Journal of Physical Chemistry - Letters. 1 (2010) [7] M. Taube, J. R Pieńkowska, A. Jarmołowski, M. Kozak, PLOS ONE 9(4) (2014) e [8] G. Ranheimer Östner, V. Lindström, P. Hjort Christensen, M. Kozak, M. Abrahamson A. Grubb. The Journal of Biological Chemistry 288 (2013)

40 O-09 Wed , Solution structure of the plant HSP90-SGT1 complex with ADP M. Taube 1 *, A. Jarmołowski 2, M. Kozak 1 1 Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland 2 Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, Poznań, Poland Keywords: small angle X-ray scattering, plant-pathogen interactions, protein structure * mtaube@amu.edu.pl Heat Shock Protein 90 kda (HSP90) protein is a molecular chaperone that assists the folding of the client proteins [1]. HSP90 takes part in the last step of this process using ATP to catalyze transition of the partially folded substrate to the stable folded state. It was also shown that HSP90 can stabilize proteins in inactive/active metastable conformation in the absence of particular stimuli for example binding partners or small molecule ligands. To the most important client proteins belongs: oncogenic kinases like BRAF and v-src, myosin heavy chain, telomerase reverse transcriptase and ligand binding domain of steroid receptors. Blocking of HSP90 activity in the cell is one of the most promising approach to inhibits tumor growth and several small molecule inhibitors are currently in the clinical studies. HSP90 protein consists of three domains: N-terminal ATPase domain, middle substrate binding domain and C-terminal domain that is responsible for the dimerization [1]. All three domains of the HSP90 protein participates in protein-protein interactions. From structural studies it's known that upon binding to the ATP molecule HSP90 change conformation from open (with non-interacting N-terminal domains) to the closed conformation (with additional dimerization of the N-terminal domains) [2]. In solution HSP90 protein exists in the equilibrium between open and closed conformation. Several proteins, called co-chaperons, binds to HSP90 protein and modulates its function by either inhibiting its ATPase activity: like p23 and HOP protein or by activating its enzymatic activity like AHA1 protein. Other proteins are responsible for recruiting special class of client proteins: for example Cdc37 protein is required for the recruiting of kinases to the HSP90 complex. In addition some of those proteins stabilizes one of the conformations of HSP90 protein. For example p23 protein stabilizes closed conformation of HSP90 in the complex with ATP. In plants and mammals HSP90 protein complex is involved in the innate immunity by the stabilizing NB- LRR (nucleotide binding leucine rich repeats receptors) receptors that recognizes pathogenic molecules or results of its action within the cell and triggers immune response against pathogenic agents [2]. For this function HSP90 protein requires two proteins: SGT1 (suppressor of G2 allele of skp1) and RAR1 (required for MLA12 resistance 1). SGT1 protein consists of three domains: N- terminal TPR domain that is required for dimerization (in plants and fungi), central CS domain that is responsible for the interaction with N-terminal domain of HSP90 and C-terminal SGS domain that is thought to be involved in the NB-LRR protein binding. RAR1 protein consist of two zinc finger domains called CHORDs and in metazoans also CS domain at the C-terminus. Both proteins have dynamic structure with well folded domains behaving as rigid bodies and dynamic unstructured regions between them. Although structure of the core of the HSP90-SGT1-RAR1 protein complex is known there is little information about the structure of the full length complex. In this work we studied low resolution structure of the plant HSP90-SGT1 complex with ADP in solution using small angle X-ray scattering technique. Using MCR-ALS analysis and ab-initio modeling we found that in the complex with the HSP90, SGT1ΔSGS protein exists as a monomer and binds to the HSP90 protein with the 1:2 stoichiometry. This is unexpected because HSP90 protein has two potential binding sites for SGT1 protein and TPR domain which is responsible for dimerization doesn't interact with HSP90 protein. By the studying of the HSP90 C-terminal truncation variant in the complex with the SGT1ΔSGS protein we showed that dimerization of HSP90 is not required for the dissociation of SGT1ΔSGS protein dimer. We also showed that binding of the CS domain alone doesn't change conformation of the HSP90ΔC protein. In the complex with SGT1ΔSGS protein and ADP molecule HSP90 protein adopts open conformation. Because HSP90 protein interacts with many partners at different steps in client folding proper stoichiometry of the functional HSP90 complex is important for its function. Asymmetric binding of its partners may be one of the ways to prevent improper assembly of the HSP90 complex. Acknowledgments: This work was supported by the grant (2012/05/N/ST3/03087) from National Science Center. [1] M. Taipale, D. F. Jarosz, S. Lindquist Nat Rev Mol Cell Biol 11 (2010) 515. [2] K. A. Krukenberg, T. O. Street, L. A. Lavery, D. A. Agard. Q Rev Biophys 44 (2011) 229. [3] Y. Kadota, K. Shirasu Biochim Biophys Acta 23 (2012)

41 O-10 Wed , Influence of microfluidic flow on amyloid aggregation of hen egg white lysozyme W. Gospodarczyk*, M. Kozak Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland Keywords: amyloid aggregation, microfluidics * Amyloid aggregation (AA) is a specific type of protein aggregation responsible for numerous serious human diseases, such as Alzheimer disease, Parkinson disease, type II diabetes, liver cirrhosis. Despite a vast number of scientific groups has been attempting to understand processes underlying AA, the exact molecular mechanism has still not been deciphered. This knowledge on AA would make seeking for therapeutic solutions much more efficient. As many different amyloid-prone proteins misfold in a similar way, there is a chance of finding one medicine for a few different diseases. AA research is not only focused on dealing with AA mechanism, but also on a quest for substances that could hamper AA aggregation, as there is a hope of finding a medicine among them. There has been an increased interest in using microfluidics a branch of technology and science that makes use of microchips devices enabling flow of samples in channels of small cross-sections in studying amyloidogenesis process. Microfluidics helped to overcome limitations of or enhance potential of traditional, 'bulk' methods. For example, there have been reported: ability to detect single nucleation sites of amyloidogenesis and trace its propagation in time, determination how flow rate of sample flowing in a chip can influence the morphology of amyloid aggregates or rapid profiling of specific proteins in bodily fluids. Some groups used microfluidics to mimic in vivo-like conditions, by testing the effect of confinement and flow on AA, but very few studied how long circulation in a chip similar to this taking place in blood vessels can itself influence amyloidogenesis. Here we mounted a microfluidic system to study the effect of long circulation on AA. We chose hen egg white lysozyme (HEWL) to study these phenomena. HEWL is a well-studied model protein, amyloid-prone, comprising 129 amino acids, taking part in bacteria lysis. It is an alpha helix-rich protein. We also used gemini surfactants in our study to seek substances effectively influencing AA. Gemini surfactants molecules consist of two polar heads with attached hydrophobic tails and a linker between the heads. They exhibit quite unusual properties as in comparison to their conventional (monomeric) surfactants they have higher surface activity, better solubility or lower critical micellization concentration and are a promising group of surfactants. The microfluidic system used in our research is not commonly used; microfluidic chips are rather utilised as mixing, droplet forming or single flow stages. The main goal of our research is to contribute to understanding of AA mechanism by revealing the role of shear forces occurring in microfluidic flow on AA. The results of measurements carried out in this project, including SAXS data, will be presented on the conference. Acknowledgments: This work was supported by a research grant (DEC-2013/09/N/ST5/02444) from National Science Centre (Poland). 31

42 O-11 Thu , Micro-X-Ray fluorescence spectrometer with X-ray single bounce metallic capillary optics for light element analysis R. Mroczka 1 *, A. Sykuła 1, E. A.Stefaniak 1,2 1 Laboratory of X-ray Optics, Centre for Interdisciplinary Research, The John Paul II Catholic University of Lublin, Konstantynów 1, Lublin, Poland, 2 Department of Chemistry, The John Paul II Catholic University of Lublin, Konstantynów 1, Lublin, Poland, Keywords: micro-xrf spectrometer, X-ray metallic capillary optics, light elements analysis * rmroczka@kul.pl In the last 20 years, due to the rapid development of X-ray optics, micro X-ray fluorescence spectrometry (micro-xrf) has become a powerful tool to determine the spatial distribution of major, minor, and trace elements within a sample. Micro-X-ray fluorescence (micro-xrf) spectrometers for light element analysis (6 Z 14) using glass polycapillary optics are usually designed and applied to confocal geometry. Two such X-ray optics systems are used in this setup. The first one focuses the primary beam on the sample; the second restricts the field of view of the detector. In order to be able to analyze a wider range of elements especialy with (6 Z 14), both sample and detector are under vacuum. Depth resolution varies between 100 μm at 1 kev fluorescence energy (Na-Kα) and 30 μm for 17.5 kev (Mo-Kα) [1,2]. In order to improve resolution at energies below 9 kev, our group designed similar spectrometer (in cooperation with PREVAC) but instead of primary polycapillary optics we applied single bounce metallic capillaries optics, designed and manufactured in our Laboratory. The vacuum chumber is currently under construction and is expected to be fully operational in September this year. Single bounce gold capillaries with elliptic internal shape have recently been redesigned and developed in our Laboratory. Surface roughness was reduced up to 0.5 nm and slope error to 0.3 mrad. For these capillaries an expected depth resolution varies from 3 µm (1 kev) and 10 µm for 9 kev (Cu-Kα). The spectrometer equipped with gold capillaries offers the possibility of elemental analysis with better depth resolution than is offerred by glass polycapillaries at energies below 9 kev. To further extend analytical capabilities of single bounce metallic capillaries, we will present a design of a micro-xrf spectrometer using synchrotron radiation (SR). Capillaries with parabolic shape will be applied in order to focus SR. This proposal can be considered as a part of our Polish Synchrotron SOLARIS. Furthermore, we will compare the capabilities and limitations of this spectrometer with others, that use laboratory and/or synchrotron sources. Acknowledgments: This work was supported and co-funded by the European Union as part of the Operational Programme Development of Eastern Poland for , Priority I Innovative Economy, Measure I.3. Support for Innovations and The National Centre for Research and Development, Project no. TANGO1,267102/NCBR/2015. [1] S. Smolek, B.Pemmer, M. Folser, C. Streli, P. Wobrauschek, Review of Scientific Instruments 83 (2012) [2] S. Smolek, T. Nakazawa, A. Tabe, K. Nakano, K. Tsuji, C. Streli, P. Wobrauschek, X-ray Spectrometry 43 (2014)

43 O-12 Thu , Solaris control and IT systems towards beamline users P. Goryl 1 *, C. J. Bocchetta 1, Ł. Dudek 1, P. Gałuszka 1, W. Kitka 1, P. Kurdziel 1, M. Ostoja-Gajewski 1, R. Różańska 2, M. J. Stankiewicz 1, K. Szamota-Leandersson 1, J. Szota 1, T. Szepieniec 2, T. Szymocha 2, A. I. Wawrzyniak 1, K. Wawrzyniak 1, M. Zając 1, Ł. Żytniak 1 1 National Synchrtoron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, Krakow, Poland 2 ACK Cyfronet AGH, Nawojki 11, Kraków 23, Poland Keywords: synchrotron radiation, tango, control system * piotr.goryl@uj.edu.pl The National Synchrotron Radiation Centre Solaris has been built in Krakow and is now in commissioning stage. Number of control and IT services has been already provided. These allow for commissioning and operation of the accelerator and both beamlines. In parallel to commissioning there is ongoing development of new services to facilitate convenient operation and usage of the systems for synchrotron light users. Tango CS control system, well established at European synchrotron laboratories, has been deployed and all controlled devices and systems has been integrated. There are three separate instances of the Tango running at Solaris. One serves accelerator and two other serve two beamlines. Several high level application has been prepared. Graphical user interfaces for beamlines are mostly prepared with usage of Sardana package and Taurus libraries At current stage end stations are provided with vendor software and are not yet integrated into the common Tango systems. However, the integration is planned for near future. Already operational network infrastructure will be soon enhanced to provide full 10 Gb/s uplinks to enable smooth data treatment for experiments producing large amount of data. It is planned to allow direct export of experiment results from an experimental station to the PL-Grid infrastructure. This will give users possibility to process data on the clusters using large number of tools provided there. A Digital User Office, which is important from the user perspective, is being prepared in collaboration with ACK Cyfronet AGH. It will be a point of access for scientists looking for experiments opportunities and letting them send and manage applications for beam time. The current status of the control and IT systems with repsect to beamlines will be presented as well as plan for future services. S-01 Tue , New developments in small spot and imaging Near Ambient Pressure XPS A. Thissen*, S. Bahr, T. Kampen, O. Schaff SPECS Surface Nano Analysis GmbH, Voltastrasse 5, Berlin, Germany * Andreas.Thissen@specs.com Over the last 15 years, Near Ambient Pressure (NAP) XPS has demonstrated its promising potential in a wide variety of applications. Starting from the Catalysis and Ice paradigm, the focus has shifted towards solid-liquid interfaces, liquid jets and in-situ electrochemistry. Initially, the experiments had to be carried out using advanced synchrotron sources to reach reasonable count rates. This is still state-of-the-art for most sensitive analyses under NAP conditions. The windowless beam entrance stages, that have been developed by SPECS over the last years utilize all capabilities of modern synchrotron beamlines for NAP-XPS. Furthermore, SPECS PHOIBOS 150 NAP offers optimized transmission for electrons, even at pressures up to and above 100mbar, so researchers can now use it with conventional X-ray and UV sources in their own laboratories, as well. Because of the widened application fields, standard XPS is now also attainable when combined with easily adjustable monochromated X-ray sources that offer stable operation, small excitations spots, and high photon flux densities, even in Near Ambient Pressure conditions. The latest designs and results are presented showing small spot performance for spot sizes < 30 µm, while also showcasing the latest implementations of imaging NAP-XPS that uses a new concept allowing for lateral resolved measurements without a compromise in count rate and usability. Highlighting on how sample environments (in situ cells for gases and liquids, electrochemical cells, gas inlets) and integration are both absolutely essential to obtain relevant results from well-defined samples, the presentation will demonstrate the use of NAP-XPS systems for high throughput-xps measurements, as well as a variety of applications. Acknowledgments: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG /09 33

44 P-01 Synchrotron radiation photoemission study of doped semiconductors valence band B.A. Orlowski*, E. Guziewicz, B.J. Kowalski, A. Reszka Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw,Poland Keywords: synchrotron radiation, resonant photoemission, Fano resonance * The synchrotron radiation as a strong continuous radiation spectrum source in the wide photon energy range (from infrared, through visible light, ultraviolet, and up to the hard X-rays) was used to induce the Fano type resonant photoemission [1,2] spectra. The 4f electrons shell contribution to the valence bands of selected semiconductors doped by rare earth atoms were studied The impurity atoms were introduced to the crystal during technology process or sequentially deposited on the crystal clean surface. The sets of photoemission spectra were acquired for the photon energy range corresponding to 4d-4f Fano resonance. The data were collected after each sequential treatment of the sample. Measured spectra showed the contribution of the 4f electrons as an additional peaks of density of states in the valence band corresponding to rare earth 2+ and 3+ ions. The presented results concern the change of the semiconductor valence band density of states caused due to contribution of 4f electrons states to the semiconductor valence band structure. It results in a new distribution of the valence band density of electronic states in semiconducting crystals, nanoelements and nanostructures. The interaction of electrons creating the structure of the valence band of a semiconducting material with the open-shell electrons of rare earth impurities strongly influences magnetic properties of systems with reduced dimensionality (like quantum dots or nanowires). Therefore revealing the contribution of such impurity states to the region of the valence band has become one of the important research problems in electronic band structure studies. The results allowed to determine the rich structure of contribution of the 4f electrons to the valence band of the semiconductor crystals and to distinguish the contributions of 2+ and 3+ valence of it. The temperature annealing leds to the change of their valence in accordance with the value expected for the cation of the host lattice of semiconductor. The binding energies and the relative intensity of the correlated peaks were determined. Acknowledgements: The work was supported by the Polish National Centre for Research and Development (NCBiR) through the project DZP/PBSII/1699/2013. [1] B.A. Orlowski Spektroskopia fotoemisyjna rezonansowa typu Fano Monography: Promieniowanie synchrotronowe w spektroskopii i badaniach strukturalnych editors: B.J. Kowalski, W. Paszkowicz, E.A. Gorlich. 2011, in PTPS. [2] E. Guziewicz et al., Appl. Surf. Science 82 (2013) 326. P-02 The limit of CdTe solubility in PbTe and the phase diagram of (Pb,Cd)Te solid solution R. Minikayev 1 *, E. Dynowska 1, A. Szczerbakow 1, A. M. T. Bell 2, W. Szuszkiewicz 1 1 Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, PL Warsaw, Poland 2 HASYLAB at DESY, Notkestr. 85, D Hamburg, Germany Keywords: synchrotron radiation, structure refinement, high temperature, phase diagram * minik@ifpan.edu.pl In search of new materials for developing of the mid- IR optoelectronic or the thermo-electric devices based on quantum dots an interesting system Pb 1-x Cd x Te solid solution attracted a lot of attention. Extremely low mutual solubility of both materials [1] results from the difference in their crystal structure rock salt (RS) for PbTe and zinc-blende (ZB) for CdTe. The objects of present investigation are unique bulk, single Pb 1-x Cd x Te crystals (with x 0.11) [2], which were obtained at the Institute of Physics of the Polish Academy of Sciences in Warsaw by SSVG method [3]. The goal of the present work was to study the structure properties and material stability of Pb 1-x Cd x Te solid solution at high temperatures and to get also new information on the temperature dependence of lattice parameters, and CdTe solubility limit in PbTe semiconductor compound. In situ high-temperature X-ray diffraction measurements were performed at the B2 beamline (Hasylab/DESY) [4], using the Debye Scherrer geometry. The samples were prepared as a mixture of powdered Pb 1-x Cd x Te crystals and fine diamond powder (in the capacity of an internal standard [5]), and placed in a thin-wall quartz capillary, rotating inside a graphite heater during measurements. The Rietveld-method [6] was used for the structural analysis. The experimental data [7-11] published previously in literature are mainly based on the results of DTA measurements performed on Pb 1-x Cd x Te solid solution with much worse crystal quality than that of present samples. The present results did not confirm the solubility limit known from the literature and suggested the necessity of some correction of the relevant phase diagram. The selected information on the Pb 1-x Cd x Te solid solution, such as a part of the phase diagram and CdTe solubility limit in PbTe for x 0.11 up to T 1100 K will be shown and discussed. Acknowledgments: This work was supported by the research grant UMO-2014/13/B/ST3/04393 from National Science Centre (Poland). [1] T. Schwarzl, E. Kaufmann, G. Springholz, K. Koike, T. Hotei, M. Yano, W. Heiss, Phys. Rev. B 78(2008) [2] M. Szot, A. Szczerbakow, K. Dybko, L. Kowalczyk, E. Smajek, V. Domukhovski, E. Łusakowska, P. Dziawa, A,. Mycielski, T. Story, M. Bukała, M. Galicka, P. Sankowski, R. Buczko, P. Kacman, Acta Phys. Pol. A 116 (2009)

45 [3] A. Szczerbakow, K. Durose, Prog. Cryst. Growth Character. Mater. 51 (2005) 81. [4] M. Knapp, C. Baehtz, H. Ehrenberg, H. Fuess, J. Synchr. Radiation 11 (2004) 328. [5] W. Paszkowicz, M. Knapp, C. Bähtz, R. Minikayev, [6] P. Piszora, J. Z. Jiang, R. Bacewicz, J. AlloysCompd. 382 (2004) 107. [7] J. Rodriguez-Carvajal, Newslett. IUCr Commission Powd. Diffr. 26 (2001) 12. [8] A. J. Rosenberg, R. Grierson, J. C. Woolley, P. Nocolik, Trans. Met. Soc. AIME, 230 (1964) 342. [9] V. Leute, R. Schmidt, Z. Phys. Chem. 172 (1991) 81 [10] N. Kh. Abrikosov, Semiconducting II-VI, IV-VI, and V-VI Compounds, Plenum Press, New York (1969). [11] H. Rutenberg, thesis, Münster (1985). [12] Y. Liu, L. Zhang, D. Yu, J. Electron. Mater. 38 (2009)

46 P-03 Atomic and electronic struture of Bi-Te films grown at various conditions by MBE method R. Rapacz 1 *, K. Balin 2, M. Wojtyniak 1, 2, J. Szade 1 1 August Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, Katowice, Poland 1 Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, Chorzów, Poland 2 Institute of Materials Science, University of Silesia, 75 Pułku Piechoty 1A, Chorzów, Poland Keywords: topological insulators, X-ray photoelectron spectroscopy (XPS), molecular beam epitaxy MBE * rapaczrafal85@gmail.com Topological insulators (TI) are new remarkable materials that have band gap in the bulk but can conduct electricity on their surface via special surface electronic states [1]. A unique feature of these states is the postulated "topological protection" towards electrons scattering, leading to high electrical conductivity. In addition, a direct relationship between spin direction and the wave vector of surfcae electrons results in a spin polarization electric current. All of these remarkable properties of TI make them the promising candidates for applications ranging from spintronics to quantum computing. One of the known TI s is bismuth telluride Bi 2 Te 3, which for which the specific properties also retain in the thin films form. The bulk component of the Bi 2 Te 3 electronic structure is characterized by a narrow energy band gap which has the value close to 0.16 ev (reported in high quality undoped samples) [2]. The Fermi level formed by the surface states is then placed roughly in the middle of the bulk gap. Bi 2 Te 3 crystallizes in the rhombohedric structure belonging to the R3m space group. The unit cell is built by quintuple layers (QL) a sequence of five atomic layers consisting of covalently bonded Te(1)-Bi-Te(2)-Bi-Te(1). The QLs are weakly bonded each-together by van der Waals interactions. The thickness of the QL in Bi 2 Te 3 is about 1 nm, while the lattice constant extends for 3 QLs in the [001] direction. Bi 2 Te 3 layers were synthesized on the silicon (100) and mica (001) substrate by molecular beam epitaxy MBE in the co-deposition mode [3]. The growth process was realized at the ultra-high vacuum conditions ( mbar). The thicknesses of the deposited films were from 10 to 30 nm. The layers had polycrystalline (silicon substrate) and mono-crystalline (mica substrate) structure. Further studies were carried out in-situ. The structure of the obtained films were studied immediately after the synthesis process by reflection high-energy electron diffraction (RHEED) and low-energy electron diffraction (LEED). These techniques revealed the hexagonal structure of surfaces. The analysis of electronic structure was carried out by X-ray photoelectron spectroscopy (XPS), it revealed no additional elements such as oxygen, carbon and other contaminants, even after several days of storage samples in a vacuum chamber. The analysis of the chemical state based on Bi 4f and Te 3d lines was in the agreement with the literature data for this compounds. In the case of polycrystalline samples the electronic structure was tested for different stoichiometries (tellurium-rich layer, the correct stoichiometry Bi 2 Te 3 and sample depleted in tellurium). For monocrystalline films the chemical states of tellurium and bismuth were studied for two different ways of growth process. In the first case sample growth was realized in assumed correct flux ratio of bismuth to tellurium (Bi/Te ratio 2/3). In the second one, the film was deposited in the environment rich in tellurium. Moreover, the XPS was used in order to specify the termination of the Bi 2 Te 3 films. The valence band structure of the Bi 2 Te 3 films was also investigated by XPS and UPS techniques. The topography of selected films was measured exsitu by atomic force microscopy AFM, thus the sample was shortly (< 5 min) introduced to the external atmosphere. The typical topography indicated the Stranski-Krastanov like growth. The flat areas constitute relatively small part of the total area of film surface. The RMS was found to be of about 9.0(1) Å. The surface is mostly formed by characteristic triangular-shaped islands reflecting the hexagonal crystal structure in the [00l] direction. A number of pyramidal-shape terraces with 1 nm high was detected which is in agreement with the thickness of a single QL. Acknowledgements: The research was supported by the Forszt project co-financed by EU from the European Social Fund. [1] M. Z. Hasan, C. L. Kane, Rev. Mod. Phys., 82 (2015) [2] K. Hoefer, C. Becker, D. Rata, J. Swanson, P. Thalmeier, L. H. Tjeng, Proc. Natl. Acad. Sci. U.S.A. 111 (2014) [3] R. Rapacz, K. Balin, A. Nowak, J. Szade, J. Cryst. Growth 401 (2014)

47 P-04 Compressibility and electronic structure variation with pressure for EuVO 4 : A combined experimental and computational study P-05 Energy transfer processes to Eu 3+ ions in K 5 Li 2 GdF 10 doped with Eu 3+, Pr 3+, Tb 3+ and Dy 3+ upon VUV excitation W. Paszkowicz 1*, J. López-Solano 2,3, P. Piszora 4, B. Bojanowski 5, A. Mujica 2, A. Muñoz 2, Y. Cerenius 6, S. Carlson 6, H. Dąbkowska 7 1 Institute of Physics PAS, al. Lotników 32/46, Warsaw, Poland, 2 Departamento de Física Fundamental II, MALTA Consolider Team, and Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Tenerife, 38205, Spain 3 Izaña Atmospheric Research Center, Agencia Estatal de Meteorología (AEMET), Tenerife, 38071, Spain 4 Faculty of Chemistry, A.Mickiewicz University, Umultowska 89b, Poznań, Poland 5 Institute of Physics, Szczecin University of Technology, Aleja Piastów 48, Szczecin, Poland 6 MAX IV Laboratory, Lund University, P.O. Box 118, SE Lund, Sweden 7 Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1 Canada Keywords: high pressure, orthovanadate, equation of state, energy gap * paszk@ifpan.edu.pl Europium orthovanadate, EuVO 4, crystallizes in the zircon-type structure (space group I4 1 /amd, Z = 4) under ambient conditions and is known to transform to a scheelite-type structure at about 8 GPa. The equation of state of this compound has already been studied. However, the reported experimental and theoretical values of the bulk modulus exhibit a considerable scatter, for both, the zircon and schheelite-type polymorphs. As for the dependence of the electronic structure with pressure, such data have not been reported yet. In the present study, structural, elastic and electronic properties of zircon-type and scheelite-type europium orthovanadate are investigated experimentally, by in-situ X-ray diffraction using synchrotron radiation, and theoretically within the framework of the density functional theory (DFT). The obtained results on bulk modulus show a perfect agreement of experiment with theory. Discrepancies between the present values and those earlier reported ones are attributed to differences in the details of the experimental procedure. The calculated band structure confirms that zircon-type europium orthovanadate is a direct-gap semiconductor, with a band-gap energy at zero pressure of 2.88 ev. The variation of electronic structure and of the bandgap with pressure is determined. 37 P. Solarz Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okólna 2, Wrocław, Poland Keywords: synchrotron radiation, energy transfer processes. solarz@int.pan.wroc.pl The X-ray examination of small crystals of K5Li2LnF10 (Ln = La Gd) has proved that the materials crystallize in a form of single phase. It is orthorhombic (space group D Pnma), the unit-cell parameters are 16 2h a = 20:775 Å; b = 7:882 Å; c = 6:963 Å; for Ln = La. The crystal structure is built from layers perpendicular to the a axis, formed by LnF 8 dodecahedra and LiF 4 tetrahedra. Rare-earth ions and lithium ions occupy sites with C S symmetry, whereas potassium and fluorine ions occupy sites with C S and C 1 symmetry. The crystal structure is uncommon in that the LnF 8 polyhedra do not share fluorine ions and the nearest rare-earth ions are separated by more than 6.8 Å. Owing to these features, exchange interactions between rare-earth ions may be neglected and multipole interactions are expected to be strongly reduced. Such a conditions allows to analyze rather pure multipole interactions between ions. Pr 3+, Tb 3+ and Dy 3+ possesses metastable multiplets situated in the blue area of the spectrum that should transfer the energy to the low positioned Eu 3+ 5 D 0 one [1]. The Pr 3+ ion can work as a sensitizer of Eu 3+ luminescence from the 5 D 0. It has been discovered that the Pr 3+ ions to transfer an energy to the Eu 3+ ions needs the presence of Gd 3+ ions. In K 5 Li 2 LaF 10 system only a luminescence of Pr 3+ was observed upon excitation of f-d bands of praseodymium [2]. It can suggest that excited the Pr 3+ ions very efficiently transfer the energy to Gd 3+ ions. Such an efficient energy transfer has been observed in other system YF 3 :Pr 3+, Gd 3+ [18]. At low temperature emission spectra (not shown here) the Pr 3+ f f emission upon UV VUV excitation was observed. It suggests that energy transfer from d levels of Pr 3+ to Gd 3+ states is thermally dependent. In the case of Dy 3+ ions, no transfer upon excitation into f-d bands of Dy 3+ was observed to Gd 3+ or Eu 3+ ions. Dysprosium is rather independent. As well as no transfer from Dy 3+ to other ions was not observed, no efficient transfer to the 4 F 9/2 multiplet of Dy 3+ was observed. The best results was found for Tb 3+ +Eu 3+ system. It occurs that upon excitation into f-d transitions bands of Tb 3+ an efficient luminescence from Eu 3+ can be observed in K 5 Li 2 GdF 10 an K 5 Li 2 LaF 10 matrixes. What is more upon excitation of Tb 3+ ions below the d levels no efficient energy transfer from Tb to Eu was observed. Such an observation is validated with analysis of the decay curves of Tb 3+ luminescence.

48 Luminescence intensity [a.u.] Eu luminescence Dy luminescence Tb luminescence Wavelength [nm] Figure 1.. Excitations spectra of luminescence recorded at Eu (red), Tb (blue), and Dy (blue) emission lines. The energy transfer from the Tb 3+ ions to the Eu 3+ one can be observed in the nm region. The 5 D 4 multiplet lifetime of 10 at% terbium doped K 5 Li 2 GdF 10 is 7500 s and is the same as in the Tb Eu system. Acknowledgments: This work was supported by POIG /09 project co-funded by European Regional Development Fund within the Innovative Economy Program. Priority I, Activity 1.1. Sub-activity 1.1.2, which is gratefully acknowledged. The research leading to these results has received funding from the European Community s Seventh Framework Programme (FP7/ ) under grant agreement n , II EC. [1] G. H. Dieke, Spectra and Energy Levels of Rare Earth Ions in Crystals, (H. M. Crosswhite and Hannah Crosswhite Editors, Wiley Interscience, New York, 1968) [2] P. Solarz, Optical Materials 31 (2008) 114. [3] T. Hirai, H. Yoshida, S. Sakuragi, S. Hashimoto, N. Ohno, Jpn. J. Appl. Phys. 46 (2007)

49 P-06 Extended abstract Electronic structure of selected ternary samarium compounds A. Bajorek 1,2 *, G. Chełkowska 1,2 1 A.Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, Katowice, Poland 2 Silesian Center for Education and Interdisciplinary Research, University of Silesia, 75 Pułku Piechoty 1A, Chorzów, Poland Keywords: rare earth alloys and compounds, photoemission spectroscopy * anna.bajorek@us.edu.pl Introduction The ternary RPdSn or RPdIn compounds have been intensively investigated in the past with respect to their crystal structure, magnetic and transport properties [1-5]. Most of them are ruled by f-d interactions. However, in compounds with hexagonal type of crystal structure some properties are connected with the frustration in R sublattice. Such interesting mechanism leads to the possible existence of the mixed valence, heavy fermion or Kondo effect. The first group of compounds RPdSn where R=Ce-Dy crystallize in the orthorhombic TiNiSi type of crystal structure (Pnma space group) whereas with R=Er-Sc crystallize in the hexagonal Fe 2 P structure (P-62m space group). The compound HoPdSn can exist in both structures and it depends on heat treatment of the sample [1,3]. The second group of compounds RPdIn (R=La-Sm,Y, Gd-Lu) with 4d elements crystallize in the ZrNiAl - type hexagonal structure (P-62m space group) [2,4,5]. The susceptibility of the policrystalline SmPdSn compound deviates form Curie - Weiss behavior. As it was previously reported this compound exhibits antiferromagnetic ordering with T N about 12K. However, in low temperature range there was noticed one more peak which is probably connected with complex magnetic structure [1,3,6]. The GdPdIn compound exhibits ferromagnetic phase transition at T C =102K and Curie Weiss behaviour with the paramagnetic Curie temperature p =96.5K [2] whereas the SmPdIn single crystal is a ferromagnet below 54K and 0.21 B /Sm along the easy magnetization a axis [4]. In mixed compounds SmPdSn 1-x In x and Gd x Sm 1-x PdIn the ordering temperatures are lower than 80K [6]. Additionally, the M(H) magnetization curves for SmPdSn and SmPdSn 0.5 In 0.5 are not saturated [6]. It may be connected with the complex magnetic structure. For Gd x Sm 1-x PdIn studied compounds M(H) is almost saturated at 7T. The value of M S equals 0.21 B /f.u, 3.36 B /f.u and 7.52 B /f.u for x=0.0, x=0.5 and x=1.0, respectively. The estimated value of magnetocalotric effect (MCE) is rather low and only for compounds which contain Gd is close to 1 [J/kgK] at the applied magnetic filed of 1T [6]. The compounds with samarium seem to be interesting due to possible existence of mixed valence state of samarium ions. As it was previously reported the free Sm atom is divalent (4f 6 )(sd) 2 while the trivalent (4f 5 )(sd) 3 state is explained as the transfer of one 4f electrons to the conduction band. The divalent state is stabilized at the surface and the trivalent is essentially visible in bulk samarium [7-10]. Some samarium compounds exhibit the intermediate valence state and even similar like the pure samarium the valence transition at the surface. The core level splitting between Sm 3+ and Sm 2+ states is about 7.6eV. The separation of the final 4f multiplet structure 4f 5 and 4f 4 allow to distinct the two possible configurations. In spite of using photoemission methods sometimes it is difficult to point out weather Sm spectra are a bulk or surface phenomena. However, one of the best method which can be used to distinguish between emission from the bulk or the surface samarium atoms is the tilting samples from the normal direction. Sometimes there is observed an increase of the intensity of Sm 3+ (3d 5/2 ) photoemission line with the decrease of the takeoff angle [7]. Here we are focused on the influence of indium and gadolinium substitution on the electronic structure of the SmPdSn 1-x In x (x=0.0, 0.5, 1.0) and Gd x Sm 1-x PdIn (x=0.0, 0.5, 1.0) compounds. To the best of our knowledge the electronic structure of studied compounds is reported here for the first time. According to this investigation we were able to deduce the valence state of samarium ions in both systems. Experimental details The polycrystalline samples SmPdSn 1-x In x (x=0.0, 0.5, 1.0) and Gd x Sm 1-x PdIn (x=0.0, 0.5, 1.0) were prepared by arc-melting from high purity elements under argon atmosphere. The melted samples were then wrapped in tantalum foil, placed in quartz tubes and annealed at 850 C for one week. After annealing all studied samples were single phase and their crystal structure was checked by means of X-ray diffraction (XRD) using Siemens D5000 diffractometer. The XPS measurements were performed with the use of PHI 5700/660 Physical Electronics spectrometer. The spectra were analyzed at room temperature using monochromatized Al K radiation (1486.6eV). The surfaces of the samples were mechanically cleaned by scrapping with a diamond file or cleaving in the preparation chamber under high vacuum of Torr. After cleaning the samples were immediately moved into the main chamber. This procedure was repeated until the intensity of C1s and O1s photoemission lines was to neglect or do not change in further cleaning of the surfaces of the samples. All XPS measurements were performed in vacuum of Torr. Results and discussion Fig.1a displays the valence band (VB) spectra in the broad energy range with core levels In4d and Sn4d. Each VB spectrum was normalized with respect to the Pd4d. The spin orbit (L-S) splitting between 4d 5/2 and 4d 3/2 indium states is about 0.85eV and between tin states 39

50 about 0.9eV. This band does not change an energy shift and forms maximum located at about 3.8eV below the Fermi level (E F ). The Gd4f level for compounds containing gadolinium is shifted in comparison to pure Gd (8eV). For GdPdIn this level is located at about 8.7eV and for Gd 0.5 Sm 0.5 PdIn at about 8.9eV below E F. This energy shift can be connected with the change of surroundings of Gd atoms The cusp visible in VB at about 5.7eV is typical for trivalent Sm 3+ (4f) states which give the contribution to VB below 5eV. The divalent Sm states should be visible above 5eV. The intensity of states at the Fermi level N(E F ) is the highest for SmPdSn and the lowest for GdPdIn (Fig.1b). It could be connected with the contribution of Sn5p and Sm 2+ (4f) which are located below 5eV. One can notice that N(E F ) is the highest for the compound which exhibits the lowest magnetization. compounds one of these peaks at about 1084eV is enhanced by In M5N45N45 Auger line. Similar behaviour is observed for divalent samarium line Sm 2+ (3d 5/2 ) located at about eV. One of its components is enhanced by In M4N45N45 Auger line (1076 ev). Therefore is difficult to estimate the 3+/2+ intensity ratio r, the coupling parameter and the occupation number of f shell n f by fitting 3d spectra using Gunnarson Schönhammer model [12]. The separation between divalent and trivalent samarium peaks equals about 8.5eV. Figure 2. XPS photoemission core level spectra of the (a) Sm3d region; (b) Sm and Gd 4d region. The 4d spectra are presented in Fig.2b. The overlap between divalent and trivalent samarium states and much more complicated multiplet structure of Sm4d than Sm3d states make the first spectra less attractive for detailed analysis. The observed Sm4d mulitiplet structure is typical for Sm 3+ states. However at about 123eV is visible sharp peak which is typical for Sm 2+ states. Some part of divalent spectrum is hidden under the stronger trivalent component. Figure 1. (a) The VB spectra in broad energy range for all studied compounds; (b) The VB near by the Fermi level (EF) normalized to Pd4d states. Inset represents the intensity of states just below EF. Fig.2a represents Sm 3d spectra taken at 45 takeoff angle and normalized to the maximum. There are visible several core level lines. The highest intensity of states is observed for Sm 3+ lines which are located at about eV (3d 5/2 ) and eV (3d 3/2 ) energy range. Each line of Sm 3+ is composed of several peaks according to multiplets produced by ionization of samarium trivalent state. However for In - rich Figure 3. XPS photoemission spectra of the samarium core level (a) 3d; (b) measured by tilting the SmPdSn sample in three chosen takeoff angles. We have also performed measurements by tilting the samples from the normal emission direction (45 ) in order to enhance emission from the bulk (30 ) and surface (60 ) states. We have not observed significant change of the (3+)/(2+) intensity ratio with the change of takeoff angle. Fig.3. represents an example of this kind 40

51 of performed measurements for the SmPdSn compound. This behaviour can be related to the roughness of the surface. Therefore we have performed all investigation on the cleaved samples and scrapped by a diamond file. The results in both cases were nearly similar. Therefore we can conclude that the mixed valence state of samarium ions observed in studied compounds is not connected with the valence transition at the surface but rather with comes from bulk states. Concluding remarks From all measurements performed for the SmPdSn 1-x In x (x=0.0, 0.5, 1.0) and Gd x Sm 1-x PdIn (x=0.0, 0.5, 1.0) compounds the following conclusions can be drawn: The change of the valence band spectra near by the Fermi level (E F ) is visible. The intensity of states at the Fermi level is the highest for the SmPdSn and the lowest for GdPdIn compounds. It is connected with the contribution of each elements to the valence band, some hybridization effects and f-d interactions. The samarium core level spectra exhibit the contribution of Sm 3+ as well as Sm 2+ states. The separation between divalent and trivalent Sm3d parts equals about 8.5eV. These two kind of peaks do not change with the tilting the samples during measurements. Therefore we claim that the mixed valence state of samarium ions in studied compounds comes from bulk states and not from the valence transition at the surface. [1] D. T. Adroja, S. K. Malik, Phys. Rev. B 45 (1992) 779. [2] M. Bałanda, A. Szytuła, M. Guillot, J. Magn. Magn. Mater. 247 (2002) 345. [3] J. Skurai, K. Kegai, T. Kuwai, Y. Isikawa, K. Nishimura, K. Mori, J. Magn. Magn. Mater (1995) 875. [4] T. Ito, K. Ohkubo, T. Hirasawa, J. Takeuchi, I. Hiromitsu, M. Kurisu, J. Magn. Magn. Mater (1995) 873. [5] Ł. Gondek, A. Szytuła, D. Kaczorowski, K. Nenkov, Solid State Comm. 142 (2007) 556. [6] A. Bajorek, G. Chełkowska, A. Chrobak, B. Sterkowicz, J. Alloys Compd. 509 (2011) [7] G. K. Wertheim, G. Crecelius, Phys Rev. B 40 (1978) 813. [8] M. G. Mason, S. T. Lee, G. Apai, R. F. Davis, D. A. Shirley, A. Franciosi, A.H. Weaver, Phys. Rev. Lett. 47 (1881) 730. [9] A. Szytuła, D. Gomółka, A. Jezierski, B. Penc, E. Wawrzyńska, A. Winiarski, Materials Science Poland 24 (2006) 557. [10] I. N. Yakovin, Surf.Sci. 601 (2007) [11] V. N. Antonov, A. P. Shpak, A. N. Yaresko, Condens. Matter Phys. 7 (2004) 211. [12] O. Gunnarson, K. Schönhammer, Phys. Rev. B 28 (1983)

52 P-07 Local structure around Co atoms in the ion and light irradiated magnetic trilayers A. Wolska 1 *, M.T. Klepka 1, I. Sveklo 2, A. Wawro 1, A. Bartnik 3, P. Mazalski 2, R. Sobierajski 1, J. Fassbender 4, A. Maziewski 2 1 Institute of Physics, Polish Academy of Sciences, Warsaw, Poland 2 University of Bialystok, Department of Physics, Poland 3 Institute of Optoelectronics, Military Academy of Technology, Warsaw, Poland 4 Institute of Ion Beam Physics and Materials Research, Dresden, Germany Keywords: synchrotron radiation, XAFS, magnetic thin layers * wolska@ifpan.edu.pl Ultrathin film systems containing magnetic component, e.g. Fe, Ni or Co with tunable magnetization direction (in-plane and out-of-plane), sandwiched between nonmagnetic metals, are of particular importance for spintronics as well as for technology of magneto-optical memory devices. The oscillatory behavior of the magnetization orientation driven by Ga + ion irradiation has been already observed in the Pt/Co/Pt sandwiches. It is possible to change irreversibly magnetic anisotropy to one of two out-of-plane magnetization branches induced by Ga + ion irradiation dose [1]. Moreover, recent investigations showed that magnetization can also be affected by femtosecond light pulses irradiation [2]. Magnetic states of the irradiated spots depend on the intensity of the femtosecond laser pulses (λ=800 nm). In case of low fluence the changes of the magnetization and magnetic anisotropy are reversible and may trigger a magnetization precession [3,4]. With higher light intensities irreversible changes of the structure are achieved [2]. In comparison with conventional thermal annealing of the sample [5] the ultrafast laser annealing provides possibility to localize deposited energy near the surface regions while substrate temperature is almost unchanged, which is important for technological applications. Presented studies were focused on the Au/Co/Pt and Pt/Co/Au trilayers irradiated with the Ga + ions and the Pt/Co/Pt trilayers irradiated with light pulses. The X-ray absorption fine structure (XAFS) experiment was performed at the BM08 beamline in ESRF. Both regions X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) were investigated. The signal was registered in a fluorescence mode at 77 K in a normal incidence configuration. The measurements were carried out at the Co K-edge for the as-grown reference and modified samples in order to determine changes in the local atomic structure around the Co atoms. The investigations were performed for the series of the Pt/Co/Au and Au/Co/Pt trilayers grown by the MBE method on the sapphire single crystal substrates and irradiated with the Ga + ions. For each configuration the as-grown samples (reference) and irradiated ones with 2 different doses were chosen. The applied doses corresponded to the level for which the out-of-plane magnetization of the sample reaches local maxima. In case of the Pt/Co/Pt trilayers the light irradiation fluences corresponded to appearance of the out-of-plane magnetization state. The whole sample surfaces were irradiated point by point with light to achieve quazi-uniformly irradiated area. Absorption (arb.u.) Energy (ev) Pt/Co/Au reference branch1 branch2 Figure 1. XANES spectra at the Co K-edge of the as-grown sample and the samples irradiated with the Ga + ions. The analysis of the samples irradiated with Ga + ions showed that in both configurations, Pt/Co/Au and Au/Co/Pt, the modifications of the atomic structure around the Co atoms are similar. This kind of evolution can be connected with the increased number of the Pt/Au neighbors in the first coordination sphere of the Co atoms. As an example, the XANES spectra for the Pt/Co/Au structures before and after irradiation are presented in Fig. 1. XANES spectra of the samples irradiated with light correspond to the spectra of the samples irradiated with the higher dose of the Ga + ions. The detailed XANES and EXAFS analysis revealed that both irradiation methods have similar influence on the local structure introducing Pt or Au atoms into the first coordination sphere. Acknowledgments: This work has been supported by the Polish National Science Center (Grant No. DEC- 2012/06/M/ST3/00475) and by the EU FP7 EAgLE project under the grant agreement REGPOT-CT We acknowledge the European Synchrotron Radiation Facility for provision of synchrotron radiation facilities and we would like to thank Dr. Angela Trapananti for assistance in using beamline BM08. [1] A. Maziewski et al., Phys. Rev. B 85 (2012) [2] J. Kisielewski et al., J. Appl. Phys. 115 (2014) [3] M. van Kampen, Phys. Rev. Lett. 88 (2002) [4] J. Kisielewski et al., Phys. Rev. B 85 (2012) [5] M. Galeotti, Surf. Sci. 297 (1993)

53 P-08 Morphological and structural modifications induced in ultrathin metallic films by nanosecond pulses from EUV laser-plasma source D. Klinger¹, I. Jacyna¹*, J. B. Pełka¹, A. Reszka¹, E. Łusakowska¹, A. Wawro¹, M. Jakubowski¹, A. Bartnik 2, R. Sobierajski¹ Various numbers of laser interaction pulses were used to control the synthesis of the nanofibrous structures. The preliminary analysis revealed that the nanostructures are formed due to the aggregation of nanoparticles with diameters varying between 30 and 90 nm. With increasing number of irradiating pulses the nanoparticles have a tendency to aggregate and merge into spheres. 1 Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw. 2 Institute of Optoelectronics, Military University of Technology, ul. gen. S. Kaliskiego 2, Warsaw,Poland Keywords: extreme ultraviolet (EUV) pulses, laser-plasma source, Au films, surface morphology, multishots * yatsyna@ifpan.edu.pl Laser-induced ablation from a solid target is known as an alternative physical method for nanofabrication. The most recent effort includes using plasmonic metal nanoparticles to improve the efficiency of quantum dot solar cells and thin film solar cells [1,2]. The main difference between nanofiber and other nanostructures (nanowire, nanotube, and nanorod) in solar cell application is the well-organized morphology structure [3]. In the present study a various number (up to 1200) of extreme ultraviolet (EUV) pulses have been used to create nanostructures at thin gold film of 80-nm thickness initially deposited onto a silicon (100) wafer using MBE technique. The source was a 10 Hz laser-plasma source based on a double-stream gas puff target created in a vacuum chamber synchronously with the pumping laser pulse. The target is formed by pulsed injection of Kr, Xe or a KrXe gas mixture into a hollow stream of helium. The EUV radiation is focused using a grazing incidence goldplated ellipsoidal collector. Spectrum of the reflected radiation consists of a narrow feature with intensity maximum at nm. After irradiations, the samples were characterized by means of the interference-polarized microscopy, scanning electrical microscopy (SEM), atom force microscopy (AFM) and synchrotron X-ray diffraction (SXRD). Figure 1. Exemplary results of surface modifications studies, obtained for 80nm Au film deposited on silicon irradiated with a single EUV pulse. 1) center: interference-polaizing microscopy image, 2) upper left: AFM map near the crater edge area, 3) bottom left: height profile along a line crossing the crater edge, 4) upper right: SEM image of the crater, 5) bottom right: X-Ray Fluorescence map (Au M-emission line) of the crater. At higher number of pulses they form entangled fibrous nanostructures. The basic mechanism of laser synthesis of nanoparticles could be explained by the accumation of the dense cloud of atoms around the laser spot of the gold target during the ablation [4-6]. Acknowledgments: The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ ) under grant agreement no and the Polish National Science Center., Grant No. DEC-2011/03/B/ST3/ [1] Aren't et al., Nano Lett. 12 (2012) [2] Jiang et al., Sol Energy Mater Sol Cells 102 (2012) 44. [3] Mahmood et al., Nanoscale Res. Lett. 9 (2014) 255. [4] Manickam et al., Opt. Exp. 17 (2009) [5] Tan et al., Opt. Exp. 17 (2009) [6] Amirkianoosh et al., Nanoscale Res. Lett. 7 (2012)

54 P-09 Investigation of morphological and structural changes in ultrathin Pt/Co/Pt trilayers induced by nanosecond pulses from EUV plasma source I. Jacyna¹*, D. Klinger¹, J. B. Pełka¹, R. Sobierajski¹, P. Dłuzewski¹, M. T. Klepka¹, E. Dynowska¹, A. Wawro¹, A. Wolska 1, M. Jakubowski¹, A. Bartnik 2, I. Sveklo 3, Z. Kurant 3, D.Eichert 4, I. Makhotkin 5, S. Yakunin 6, A. Maziewski 3 ¹Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw 2 Institute of Optoelectronics, Military University of Technology, ul. gen. S. Kaliskiego 2, Warsaw, Poland 3 Laboratory of Magnetism, Faculty of Physics, University of Bialystok, K. Ciolkowskiego 1L, , Bialystok, Poland 4 Elettra-Sincrotrone Trieste, S.S. 14 Km in Area Science Park, Basovizza, Trieste, Italy 5 MESA+ Institute for Nanotechnology, University of Twente, Netherlands 6 NRC Kurchatov Institute, Moscow, Russia have been studied by interference optical microscopy, atomic force microscopy and scanning electron microscopy. The irradiation s induced structural changes of the trilayer were characterized by means of TEM analysis of sample s cross-sections and X-ray standing wave experiment with fluorescence detection. The obtained morphological and structural modifications were compared with the changes of magnetization. Correlation between magnetic anisotropy and structure of the Co-Pt interfaces were observed. Moreover correlation of induced perpendicular magnetic anisotropy with the morphological changes on the top surface in the irradiated regions were found. Keywords: nanosecond pulse, laser-plasma source, EUV light, ultrathin films, Pt/Co/Pt, structure modification * yatsyna@ifpan.edu.pl Ultrathin film systems containing a magnetic element, e.g. Fe, Ni or Co, sandwiched between nonmagnetic noble metals, with tunable magnetization orientation (in-plane and out-of-plane) are of particular importance for spintronics as well as for technology of magneto-optical memory devices [1,2]. The perpendicular magnetic anisotropy (orientation of magnetization easy axis perpendicular to the film surface) is considered in the systems to be related mainly to the structural details of magnetic film and interfaces. In case of a Pt/Co/Pt trilayers irradiated by different light sources [3,4] and ions [5,6], an out-of-plane to inplane magnetization reorientation phase transition together with an intermixing and disordering at the Co Pt interfaces were observed. The aim of this work is to study the detailed structural properties of trilayer systems containing ultrathin (a few nm) Co layer sandwiched between Pt films (of several nm thickness each). The structure of the studied samples was modified by irradiation with nanosecond EUV pulses, characterized by a Gaussian-like spatial intensity distribution, generated by a laser produced plasma source. The irradiations have been carried out both in the single shot and in multi shot modes, with various irradiation fluencies. Morphological changes, together with structural modifications induced on the irradiated surface spots, Figure 1. Correlation of the diameter of surface morphology and magnetical remanescence modifications regions measured at trilayer 250Pt/30Co/30Pt by means of interferencepolaryzing microscopy and Magneto-optic Kerr effect, respectively. Acknowledgments: This work was partially supported by the Polish National Science Center (Grant No. 2012/06/M/ST3/00475). The research leading to these results has received funding from the European Community s Seventh Framework Programme (FP ) under grant agreement n (CALIPSO) and from the EU FP7 EAgLE project under the grant agreement REGPOT-CT [1] N. W. E. McGee, M. T. Johnson, J. J. de Vries and J. Aan de Stegge, Appl. Phys. 73 (1993) [2] B. Heinrich, Ultrathin Magnetic Structures, Springer, Berlin, 1994) [3] J. Kisielewski et al., Journal of Applied Physics 115, (2014) [4] E. Dynowska, et. al., Structural investigation of ultrathin Pt/Co/Pt trilayer films under EUV irradiation; ISSRNS 2014( submitted to Rad. Phys. Chem. [5] A. Maziewski, P. Mazalski, Z. Kurant, et al., Phys. Rev. B 85 (2012) [6] M. Sakamaki, et. al., Phys. Rev. B 86 (2012)

55 P-10 Structural properties of Fe/Pt multilayers before and after ion beam irradiation thickness. This is the evidence of very sharp interfaces inside the multilayer. E. Dynowska 1 *, A. Marynowska 1, L. T. Baczewski 1, J. Fassbender 2, R. Böttger 2 1 Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw, Poland 2 Helmholtz Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, Dresden, Germany Keywords: X ray diffraction, thin metallic multilayers, molecular beam epitaxy * dynow@ifpan.edu.pl Figure 1. X-ray diffraction pattern in the vicinity of 222 Pt reflection performed for the as grown sample. FePt alloys are extremely promising candidates for future high density recording media due to its high magnetic anisotropy up to ergs/cm 2 [1]. The reason for such high magnetic anisotropy is attributed to the transformation of the disordered face-centered cubic (fcc) FePt alloy to the ordered face-centered tetragonal (fct) one. Typical method of obtaining fct FePt alloy is post annealing of Fe/Pt multilayers. However, the high temperatures (up to 700 C), used in this method are not compatible with magnetic media manufacturing techniques. The better method for intermixing of the Fe/Pt system is ion beam irradiation which does not require such high temperatures [2]. The intermixing of the Fe/Pt system may result in the formation of several different phases: disordered fcc FePt, ordered fct FePt, iron-rich Fe 3 Pt and platinum-rich FePt 3. In this paper we report the results of structural characterization of several Fe/Pt multilayer samples Al 2 O 3 (0001)/Pt10nm/(Fe1nm/Pt1nm) 15/Pt10nm before and after Ne + ion beam irradiation. All samples of 5 3,3 mm size were grown simultaneously in molecular beam epitaxy system at room temperature in Torr vacuum. All pieces were irradiated with Ne + ions of the energy 25 kev but each with different dose ( ions/cm 2 ), respectively. The crystal structure of all samples has been examined by X-ray diffraction methods. The PANalitycal Empyrean X-ray diffractometer with Cu K 1 radiation, equipped with the Johansson monochromator Ge(111) in the incident beam and a linear semiconductor strip detector has been used. The symmetrical and asymmetrical X-ray diffraction patterns were performed. The examples of X-ray symmetrical patterns from the as grown and irradiated multilayer are shown in Figures 1 and 2. On the basis of the first diffraction pattern (Fig.1) it can be concluded that the Pt layers as well as the superlattice Fe/Pt grow in the [111] direction. The peaks marked by -1, -2 and +1 are the satellite lines from the superlattice from their positions the thickness of the Fe/Pt bilayer (superlattice period C) can be calculated. The X-ray pattern of the as grown sample in the vicinity of 111 Pt reflection (not shown here) shows also the presence of thickness fringes originating from the individual layers, as well as from the whole structure 45 Figure 2. X-ray diffraction pattern in the vicinity of 222 Pt reflection sample irradiated with 25 kev Ne + ions of ions/cm 2 dose. As it is seen in Figure 2 even the smallest of the applied doses of irradiation completely changed the crystal structure of the multilayer as a result two kinds of disordered fcc FePt alloys (W 1 and W 2 ) with different composition have been formed. The intermixing of the Fe/Pt superlattice caused the creation of the alloy with composition of about Pt 0.50 Fe The composition of this alloy practically does not change with increasing dose. The reason of the W 1 alloy formation is the diffusion of the Fe atoms to the platinum cover layer the Fe content in this alloy increases with the increasing dose from Fe 0.14 Pt 0.86 to Fe 0.26 Pt Peak marked as Pt is related to Pt buffer layer and it s position is the same as that for the as grown sample. The quality of the thickness fringes from this layer deteriorates with the increasing dose what evidences substantial damaging of respective interfaces. Acknowledgments:This work was partially supported by the European Regional Development Fund within Innovative Economy Operational Programme: POIG /09. [1] V. R. Reddy, S. Kavita, S. Amirthapandian, A. Gupta, B. K. Panigrahi, J. Phys. Condens. Matter.18, (2006) [2] D. Ravelosona, C. Chapptert, V. Mathet, H. Bernas, J.Appl. Phys. 87, (2000) 5771.

56 P-11 XANES and EXAFS studies of bioactive metalloorganic complexes in solid and liquid state M. T. Klepka 1 *, A. Wolska 1, A. Drzewiecka-Antonik 1, P. Rejmak 1, G. Aquilanti 2 group attached at two different positions, C6 and C8, to the rigid coumarin ring. The electrochemical method was applied for the synthesis of the complexes. a O OH CH 3 b CH 3 1 Institute of Physics Polish Academy of Sciences, Warsaw, Poland 2 Elettra - Sincrotrone Trieste, Italy H 3 C H 3 C O O HO O O Keywords: coumarin, metal-organic ligand complexes, XANES, EXAFS * mklepka@ifpan.edu.pl Extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopies already demonstrated their usefulness in studies of disordered systems. These techniques provide information about local atomic neighborhood and coordination polyhedra around metal cations regardless of the state or crystallographic form of the investigated material. It is especially important for structural studies of compounds without long range order like copper(ii) complexes of coumarins. The natural as well as synthetic coumarins, therein hydroxycoumarins, exhibit a large spectrum of biological activity. Such derivatives proved usefulness as anticoagulants [1], antibacterial agents [2], antifungal agents [3], biological inhibitors [4], chemotherapeutics [5] and as bio-analytical reagents [6]. It has been found out that coordination of metal ions to therapeutic agents (such as simple coumarins) can improve their efficacy and accelerate bioactivity. In many cases such metal complexes are more potent and less toxic comparing to the parent drug. Therefore, among others, also biologically active metal complexes of coumarin based ligands are being widely investigated. Creaven et al. have investigated the antimicrobial activity of a number of coumarin complexes with silver(i), copper(ii) and manganese(ii) ions. For example, the Cu(II) complexes exhibit antifungal activity against a clinical strain of C. albicans comparable to that of the commercially available antifungal drugs, i.e. ketoconazole and Amphotericin B [7]. Our studies presented here were focused on comparison between solid and liquid state of two bioactive hydroxycoumarin complexes. Our goal was to try to simulate environment similar to one during biological activity tests and human body. As solvents DMSO dimethyl sulfoxide and DMF dimethylformamide were used. Previously synthesized copper(ii) complexes of two hydroxyligands: HL1 and HL2 (Figure 1) were used. These ligands have acetyl H 3 C O Figure 1. Molecular structure of ligands a - HL1 and b - HL2 XAFS measurements were performed at the beamline I811 at MAX-lab in Lund, Sweden and XAFS beamline at Elettra in Trieste, Italy. First samples in the form of microcrystalline powder were investigated in Lund. After that solutions of complexes in organic solvents (DMSO; DMF) were measured in Trieste. Methodology of the analysis included several steps. First, the compounds were initially characterized by Fourier transformed infrared spectroscopy (FTIR). Next, EXAFS data were fitted in order to get information about local atomic order. XANES spectra revealed that Cu in complexes is mostly 2+. Then, obtained results were used to find proper model with help of the density functional theory (DFT). Finally full potential multiple scattering XANES calculations were performed. Results of structural analysis for compounds in the form of microcrystalline powder enabled us to propose mechanism of metal-organic ligand interaction. Some differences were observed between powder form and solutions of respective complexes. During the presentation details will be discussed and compared with results from biological activity tests. Acknowledgments: Experimental research was funded from the Polish National Science Centre (Grant No. UMO- 2012/07/D/ST5/02251), The synchrotron experiment was partially supported by the Baltic Science Link project coordinated by the Swedish Research Council, VR. This research was supported in part by PL-Grid Infrastructure. Financial support from the EU FP7 EAgLE project under the grant agreement REGPOT-CT is gratefully acknowledged. [1] J. W. Suttie, Clin. Cardiol. 13 (VI) (1990) 16. [2] A. H. Bedair, et al., Il Farmaco 55 (2000) 708. [3] T. Patonay, et al., Pharmazie 39 (1984) 86. [4] C. Gnerre, et al., Med. Chem. 43 (2000) [5] D. A. Egan, et al., Cancer Lett. 118 (1997) 201. [6] M. Jime nez, et al., J. Chrom. A 870 (2000) 473. [7] B. S. Creaven, et al., J. Inorg. Biochem. 103 (2009)

57 P-12 XAFS estimation of the catalytic centre in double metal cyanide catalysts K. Lawniczak-Jablonska 1 *, A. Chruściel 2 1 Institute of Physics, Polish Academy of Sciences, Lotnikow Str 32/46, Warsaw, Poland 2 MEXEO, Kędzierzyn-Koźle, Energetykow Str 9, Poland Keywords: DMC catalysts, XAFS. * jablo@ifpan.edu.pl agreement with the model. Therefore, the reference material was not fully hydrated. The EXAFS spectra of investigated materials at Zn K-edge and their FT modules noticeably differed (Fig. 1). In the case of catalysts, the number of atoms in the subsequence coordination spheres was smaller than in the model of reference material. Finally, it was proved, that the atomic order resembles rather a tetrahedral structure with four N atoms around Zn (anhydrous phase) instead of 6 in cubic structure (hydrated phase). Therefore, the stoichiometry and structure change in catalysts after introduction of ligands. Double metal cyanide catalysts (DMC) are widely exploited in industrial ring opening polymerization of the epoxydes [1]. This group of catalysts is successfully applied and continuously improved for few decades, but the knowledge on the molecular nature of their particularly high activity and selectivity is limited to some phenomenological hypotheses. To shine some light on the relation between structural and chemical properties of DMC catalysts and their activity, XAS studies were performed in cooperation with MEXEO Kędzierzyn-Koźle Company. The DMC catalysts (MEO- DMC) and the reference material were synthesized by MEXEO. The reference material was the hydrated trizinc bis[hexacyanocobaltate(iii)] compound (Zn 3 [Co(CN) 6 ] 2 nh 2 O) of negligibly low catalytically activity without practical application. Only after introduction to its structure appropriate kinds of organic ligands, catalytic activity increases. The synthesis started from K 3 [Co(CN) 6 ] 2 and ZnCl 2 raw materials. In the investigated samples, the tert-butanol ( t BuOH) or 1,2- dimethoxyethane (glyme)) ligands were introduced in catalyst preparation process. These ligands are the most frequently used in commercial application of DMC family of catalysts. The commercial DMC catalyst was used as a comparative DMC catalyst. All samples were in the form of powder. The introduction of the ligands change the morphology of the DMC material from cubic observed in reference material to kind of irregular sheets with very extended surface. The EXAFS analysis of the Zn and Co K-edges was performed to exam the local atomic order around Zn and Co atom in the reference material, the MEO-DMC catalysts and the commercial catalyst. The XAS measurements were performed at SOLEIL, France (SAMBA station). In agreement with the XRD results, the model for the reference material was assumed to be a cubic structure (Fm-3m) with water and a lattice constant of nm. This model provides for the EXAFS analysis the starting parameters including the number, kinds and distance of atoms in the subsequence coordination shells in ideal (Zn 3 [Co(CN) 6 ] 2 12H 2 O) reference material. The EXAFS analysis of the Zn and Co K-edge indicated, that in the considered reference material, instead of 24, only few oxygen atoms were detected. Furthermore, the number of other atoms in the coordination spheres was in the 47 Figure 1. The comparison of FT modules of the experimental Zn K-edge spectra for investigated materials. Several models of atomic order around Zn were considered. The best fit to the EXAFS data was for the model assuming that majority of Zn atoms in MEO- DMC catalyst still have the local atomic order as should be in the reference anhydrous material with tetrahedral structure but about 20% of them have Cl in the first coordination sphere (Fig. 2). Figure 2. Fit of the EXAFS data to the final model of the local atomic structure around Zn atoms for MEO-DMC catalyst. The local atomic structure around Co atom was practically not changing for all investigated materials (Fig. 3). Moreover, has the atomic order like in the hydrated reference material (octahedral) with 6 C atoms as near-neighbors. This confirmed that Co metallic centre is not active during the catalyst preparation. On the basis of performed analysis, the following model of investigated DMC catalysts is proposed.

58 Catalysts form cluster-like complexes with the Co atomic structure not affected as compare to reference hydrated (cubic) material. Figure 3. The comparison of FT modules of the experimental Co K-edge spectra for investigated materials. The Zn atoms inside the clusters have atomic order like in anhydrous reference material (4 N atoms). This explains this part of the Zn atoms in EXAFS analysis which have an atomic order similar to that in the reference anhydrous material. At the surface of the clusters, Zn atoms are bounded partially with groups of cyanide and with chlorine atoms from the ZnCl 2 or oxygen atoms from the ligand. The amount of Cl detected by EXAFS in all investigated samples was in agreement with that estimated by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) measurements. This model explains the fact that X-ray diffraction pattern for investigated catalysts cannot be described by any of know phase. The atomic order around majority of Zn atoms resembles anhydrous phase, but that around Co hydrated phase. The performed analysis of EXAFS provided direct experimental evidence for the phenomenological hypotheses postulated by Zhang et al., [2] and for calculation performed by Wojdeł et al., [3]. [1] A. Chruściel, W. Hreczuch, J. Janik, K. Czaja, K. Dziubek, Z. Flisak, A. Swinarew,: Ind. Eng. Chem. Res. 53 (2014) [2] X.-H. Zhang, Z.-J. Hua, Sh. Chen, F. Liu, X.-K. Sun, G.-R. Qi, Appl. Catal. 325 (2007) 91. [3] J. C. Wojdeł, S. T. Bromley, F. Illas, J. C. Jansen, J. Mol. Model. 13 (2007)

59 P-13 Trimeric surfactants new effective carries for gene therapy Ż. Kołodziejska*, Z. Pietralik, M. Kozak Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland Keywords: gene therapy, trimericsurfactants, lipoplex * One of the most important goal of modern medicine is to develop biocompatible, effective, non-toxic and synthetic systems to transport of therapeutic substances into cells. The selection of the most suitable carrier can provide successful treatment for both congenital andacquired diseases. Due to the low toxicity, biocompatibility, and simplicity of the manufacturing process, complexes based on surfactants and lipids are thought to have great potential as carriers, especially for gene therapy, in which genetic material is the therapetic substance [1, 2]. Such systems represent a compromise between the biocompatibility provided by natural lipid molecules and toxicity of surfactants, which presence is necessary due to binding abilities that ensure the effectiveness of complexation of nucleic acids [3, 4]. Our studies focus on trimeric (also known as trigemini) surfactants as they are characterised by better surface-activeproperties, than their dimeric or monomeric counterparts. This study was performed on mixed system composed of two types of trigemini surfactant and lipids (DMPC, DOPE, DPPC). The ability to bind nucleic acids was tested on three types of DNA varying in size i.e. 21 bp, 200 bp or 20 kbp. To obtain structural information about formed systems, small angle X-ray scatering (SAXS) measurements using synchrotron radiation were performed at Beam Line P12 (EMBL Outstation c/o DESY Hamburg, Germany).Additionally, to characterize conformational changes in thelipid structures and to investigate the nature of phase transitions in solution, infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used. To get an insight into process of complex formation with nucleic acid, circular dichroism (CD) spectroscopy and electrophoretic experiments were performed. Results indicate that trigemini surfactants formed stable complexes with DNA more efficiently than gemini surfactants, (i.e. at lower concentrations in solution). The addition of lipids also improves the efficiency of the complexation. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC-2011/01/B/ST5/ [1] D. W. Emery, Clin. Appl. Immunol. Rev. 4 (2004) 411. [2] D. Ibraheem, A. Elaissari, H. Fessi, Int. J. Pharm. 459 (2014) 70. [3] R. Zana, Adv. Colloid Interface Sci. 97 (2002) 205. [4] L. Karlsson, M. C. P. van Eijk, O. Söderman, J. Colloid Interface Sci. 252 (2002)

60 P-14 Structural studies of nanosystems based on zwitterionic sugar-based surfactants as innovative gene delivery systems M. Skupin 1 *, Z. Pietralik 1, K. Sobczak 2, R. Zieliński 3, M. Kozak 1 1 Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland 2 Department of Gene Expression, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, Poznań, Poland 3 Faculty of Commodity Science, University of Economics, Al. Niepodległości 10, Poznan, Poland Keywords: small angle X-ray scattering, gene therapy, sugarbased surfactants, cytotoxicity, circular dichroism * misiaskupin@gmail.com One of the most important advantages of synthetic non-viral drug delivery systems is the improved transfection efficiency [1]. Broad range of amphiphilic dicationic surfactants, known as gemini surfactants, is currently studied for gene delivery purposes [2]. Unfortunately the disadvantage of these systems is their cytotoxicity. The presented here studies indicated, that an effective complexation between DNA or RNA and zwitterionic sugar-based surfactants leads to the compaction of the nucleic acids. This effect has potential applications for preparation of gene delivery systems with reduced toxicity and improved transfection efficiency. Such systems can protect the genetic material against the degeneration by intracellular nucleases and also can promote the penetration of nucleic acid into the target cell. The influence of various concentrations of selected surfactants on different structural forms of DNA (single strand DNA, double strand DNA and RNA oligomers) was investigated using circular dichroism (CD) spectroscopy and gel electrophoresis. The small angle scattering of synchrotron radiation (SR-SAXS) studies were also performed on selected lipoplexes based on short DNA and RNA double stranded oligomers (21 bp), single strand DNA (23-mer) and sugar-based surfactants. The SAXS data for nanosystems studied were collected on P12 beam line of EMBL Hamburg Outstation at PETRA III storage ring (DESY). A series of toxicity and transfection tests of these lipoplexes were performed using HeLa and fibroblasts (GM04033 and GM07492 line). The results obtained revealed the unique properties of such designed systems. Even small amounts of lactosebased surfactants, that bind strongly to DNA or RNA, can cause a change of nucleic acid from one conformation to another. We can conclude, that sugar-based surfactants could be useful as potential vectors for transfer genetic material into mammalian cells during non-viral gene therapy. Thanks to their construction these carriers can be able to deliver the genes of various sizes to the cells, which is difficult using viral gene delivery systems. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC- 2011/01/B/ST5/ [1] E. Cevher, A. Sezer, E. Çag lar, Recent Advances in Novel Drug Carrier Systems, [2] Z. Pietralik, R. Krzysztoń, W. Kida, W. Andrzejewska, M. Kozak, Int J. Mol. Sci. 14 (2013)

61 P-15 Studies of dsdna and sirna oligomers in complexes with tricationic surfactants using biophysical methods W. Andrzejewska*, M. Skupin, M. Kozak Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznan, Poland Keywords: gene therapy, dsdna, sirna, tricationic surfactants, X-ray scattering, circular dichroism, gel electrophoresis, cell cultures * Among the most intensively studied areas of the science today we can find gene therapy the innovative and probably the most promising method for treatment of all types of diseases so far incurable. The aim of gene therapy is the induction of changes in the gene machinery of diseased cells that cause blockage or destruction of abnormal genes or contribute to the production of factors acting antagonistically. This could be done by introducing a short RNA molecules (transgenes) which are able to act in this way. Unfortunately, in practice, it creates a lot of problems, mostly in the introduction of these nucleic acid to the cell without inducing immunological response. The solution is to find a suitable carriers, which could solve these problems[1-4]. Our research indicates that this potential have spatial structures formed by self-organized quaternary ammonium salts surfactants [5]. In the range of new amphiphilies, tricationic surfactants, featuring three hydrophobic chains (hydrophobic moieties) and three polar head groups linked by a spacer, seems to be quite promising. Their physicochemical properties making them able to create a stable, biocompatible complexes with dsdna and sirna. In this work we present results of small angle X-ray scattering (SH-SAXS), circular dichroism (CD), gel electrophoresis studies and cellular tests of the complexes formed between two tricationic surfactants: 1,2,3-propantriol [oxomethyl-3-(1-dodecylimidazolium)] chloride and 1,2,3-propantriol [(oxomethyl) dimethyldodecylammonium] chloride with short 21 bp double stranded nucleic acid oligomers dsdna and sirna [6-7]. First of all we conducted complexation process, than characterized main structural parameters of the obtained structures (like size, shape, spatial structure, resultant charge, morphology), described conformational changes of nucleic acids bound in them and finally we prepared probable models of these complexes. Moreover we performed also toxicity tests on HeLa and human fibroblasts cell cultures using our systems to find out their influence on these lines. All these results proved to be very interesting. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC-2011/01/B/ST5/00846). [1] R. Zieliński, Surfactants structure, properties, applications (in Polish), WUP (2009) Poznan. [2] Ch. Wang, X. Li, D. Wettig, I. Badea, M. Foldvarid, M.E. Verrall, Phys. Chem. Chem. Phys. 9 (2007) [3] C. Amoruso, T. Lagache, D. Holcman, SIAM J. Appl. Math. 71(6) (2011) [4] B. Ma, S. Zhang, H. Jiang, B. Zhao, H. Lv, J. of Cont. Rel. 123 (2007) 184. [5] Z. Pietralik, R. Krzysztoń, W. Kida, W. Andrzejewska, M. Kozak, Int. J. Mol. Sci. 14 (2014) [6] J. Pernak, A. Skrzypczak, G. Lota, E. Frąckowiak, Chem. Eur. J. 13 (2007) [7] F. Mutelet, J. Ch. Moise, A. Skrzypczak, J. Chem. Eng. Data 57 (2012)

62 P-16 Physical characterization of BMV capsid protein M. Kręcisz 1 *, J.D. Rybka 1 ** S. Haracz 1, A. Strugała 1,2, I.Zhukov 3, A. Urbanowicz 2, M. Figlerowicz 2, M. Kozak 4, M.Giersig 1,5 1 Faculty of Chemistry, Wielkopolska Center for Advanced Technologies, Adam Mickiewicz University, Umultowska 89C, Poznan, Poland 2 Institute of Bioorganic Chemistry, Polish Academy of Science, Z. Noskowskiego 12/14, Poznan, Poland 3 Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warszawa, Poland 4 Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznan 5 Institut für Experimentalphysik, Freie Universität Berlin, Arnimalle 14, Berlin, Germany Keywords: synchrotron radiation, virus, dynamic light scattering, transmission microscopy, secondary structure, spectroscopy FTIR, circular dichroism, nmr * mkrecisz@amu.edu.pl ** jrybka@amu.edu.pl Brome Mosaic Virus (BMV), an icosahedral RNA plant virus, can be used to create nanocages and viruslike particles (VLP's). Virus capsids packed with nanoparticles are also very promising tool for medical applications. Particularly VLP with magnetite cores may be useful in hyperthermic cancer therapy, Magnetic Resonance Imaging (MRI) and processes connected with sorting and recognition of cells. The first step to form the VLP is the characterization of the virus capsid proteins by physical methods. Cryo- TEM study was conducted to determine the size and morphology of the native capsid. Low resolution structure and size distribution was confirmed by: Small Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS) and Nuclear Magnetic Resonance (NMR). Obtained scattering curves allowed us to create a model of BMV shell. Typical for plant viruses ph-depending closing of capsid pores was also studied. This can be useful for packaging of nanoparticles into the viral capsid. Attenuated Total Reflectance Fourier Transformed Infrared Spectroscopy (ATR-FTIR) and Circular Dichroism (CD) techniques was also made to examine changes in the secondary structure as a function of ph of the solution. One of the method of creation of VLP with nanoparticles is dialysis of ions through the pores and their reduction inside of the capsid. Formation of the magnetite nanoparticles from iron ions within the BMV capsid has been made and confirmed by DLS and Mass Spectroscopy (MALDI-TOF) studies. Acknowledgments: This work was supported by UMO-2012/06/A/ST4/00373 grant from National Science Centre (Poland) [1] P. I. Haris, F. Severcan, J Mol Catal B-Enzym 7 (1999) 207. [2] M. Casselyn, et al., Acta Cryst., D57 (2001) [3] S. L. Calhoun, A. L. Rao, Arch Virol. 153 (2008)

63 P-17 Valence and ionic lowest-lying electronic states of small esters studied by high resolution vacuum ultraviolet photoabsorption, photoelectron spectroscopy and ab initio calculations M. A. Śmiałek 1;2 *, M. Łabuda 3, J. Guthmuller 3, S. V. Hoffmann 4, N. C. Jones 4, M. A. MacDonald 5, L. Zuin 5, M.-J. Hubin-Franskin 6, J. Delwiche 6, D. Duflot 7, N. J. Mason 2, P. Limão-Vieira 2,8 [2] and ethyl acetate [3], studied experimentally as well as theoretically. The high-resolution VUV photoabsorption spectra shown here were measured at the UV1 beam line, using the ASTRID synchrotron facility in Aarhus University, Denmark. The photoelectron spectra of esters were measured either at the VLS-PGM beamline at the Canadian Light Source facility in Saskatoon, Canada, using a Double Toroidal Coincidence Spectrometer or at the Université de Liège, Belgium, using the He(I) radiation. 1 Department of Control and Power Engineering, Faculty of Ocean Engineering and Ship Technology, Gdańsk University of Technology, Gabriela Narutowicza 11/12, Gdańsk, Poland 2 Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom 3 Department of Theoretical Physic and Quantum Information, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Gabriela Narutowicza 11/12, Gdańsk, Poland 4 ISA, Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark 5 Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon SK S7N 2V3, Canada 6 Département de Chimie, Université de Liège, Institut de Chimie-Bât. B6C, B-4000 Liège, Belgium 7 Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), UMR CNRS 8523, Université Lille 1 Sciences et Technologies, F Villeneuve d Ascq Cedex, France 8 Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal Keywords: synchrotron radiation, photoelectron, photoabsorption spectra, esters, ab initio calculations * smialek@pg.gda.pl Esters are an important class of oxygenated volatile organic compounds used in food flavorings, perfumes and other cosmetic products. They are present in fruits and pheromones and are emitted to the atmosphere naturally. Esters are also formed in the atmosphere as a product of the oxidation of ethers. Some of them form poly-molecule chains and are used in plastics. Phosphoesters form DNA backbone, while nitroesters are known for their explosive character. Some small ester molecules were reported to be found in the interstellar space. It was also shown that esters may be a product of hydroxyl radical-initiated oxidation of various ethers in troposphere. Although esters are not very toxic, their degradation in the atmosphere may lead to production of more toxic and reactive species. In our present study we have focused on smaller monoesters. The main purpose of our work is to understand, how the carboxylic and alcohol group distribution within the molecules influences their physical properties and reactivity. In this communication we would like to present our findings for ethyl formate [1], isobutyl formate (Figure 1) 53 Figure 1. Photoelectron (upper) and photoabsorption (lower) spectrum of isobutyl formate, C5H10O2. The results presented here are supported by ab initio calculations in order to allow for correct assignment of all vertical and adiabatic ionization energies resolved in the spectrum as well as proper assignment of valence states and Rydberg transitions found in the photoabsorption spectrum. Acknowledgments: The authors wish to acknowledge the beam time at the ISA synchrotron at Aarhus University, Denmark, supported by the European Union (EU) I3 programme ELISA, Grant Agreement No We also acknowledge the financial support provided by the European Commission through the Access to Research Infrastructure action of the Improving Human Potential Programme. A part of research described in this paper was performed at the Canadian Light Source, which is supported by the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Province of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. All calculations have been performed at the Academic Center (CI TASK) in Gdańsk and at Universitätsrechenzentrum of the Friedrich-Schiller University in Jena. [1] M. A. Śmiałek et al., J. Chem. Phys. 141 (2014) [2] M. A. Śmiałek et al., J. Phys. Chem. A, submitted [3] M. A. Śmiałek et al., in preparation

64 P-18 Spectroscopic characterization of human cystatin C and its mutants Z. Pietralik 1 *, A. Szymańska 2, M. Kozak 1 1 Department of MaclomolecularPhysics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland 2 Department of Medicinal Chemistry, Faculty of Chemistry, University of Gdansk, Sobieskiego, Gdansk, Poland Keywords: Human Cystatin C, secondary structure, FTIR, CD * zuzannap@amu.edu.pl Human cystatin C (HCC) is a small β-protein consisting of 120 amino acidsthat is found in all nucleated cells. Physiologically, its function is to regulate the catalytic activity of cysteine proteas. This protein is also associated with two types of amyloid disorders. First one is hereditarycystatine C amyloid angiopathy (HCCAA), which is related to the L68Q mutation and it is causing brianhemorrages [1]. The second disorder is connected with deposition of amyloid β-fibrils where the wild-type cystatin C is present as co-precipitant [2,3]. The aim of our studies was the spectroscopic characterisation of the native and mutated forms of human cystatin C in solution.particullary mutants V57N, V57P, V57G, V57D and L68Q were tested. The secondary structure content in the broad range of temperatures, in solution was evaluated on the basis of Fourier transformed infrared spectroscopy (FTIR) and circular dichroism spectroscopy (CD). Additionally the overall fluerescence and dynamic light scattering (DLS) was also recorded. Fourier self deconvolution procedure was used to assign all the components of the Amid-I band to particular secondary structures [4]. Obtained data was compared with CD-based percentage content of secondaty structures, for which spectra were recoreded in temperature range from 5 to 70 ºC.The obtained results have shown that there are differences in content of secondary structures between wild type of HCC and its mutants. For example the L68Q mutant contain the most percentages of β-sheets of all tested proteins wheras V57P mutant has the richest α-helix content. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC-2012/06/M/ST4/00036 [1] G. Guðmundsson, J. Hallgrímsson, T. Á. Jónasson, Ó. Bjarnason, Brain. 95 (1972) 387. [2] E. Levy, Expert Rev. Neurother. 8 (2008) 687. doi: / [3] R. Craig-Schapiro, M. Kuhn, C. Xiong, E.H. Pickering, J. Liu, T. P. Misko, et al., PLoS ONE. 6 (2011) e [4] P. Garidel, H. Schott, BioProcess Int. (2006). P-19 Hydrogen migration in formation of NH(A 3 Π) radicals in photodissociations of isoxazole and pyridine molecules T. J. Wasowicz 1 *, A. Kivimaki 2,3, M. Coreno 3,4, M. Zubek 1 1 Department of Physics of Electronic Phenomena, Gdańsk University of Technology, ul. G. Narutowicza 11/12, Gdańsk, Poland 2 CNR-IOM, Laboratorio TASC, Trieste, Italy 3 Gas Phase beamline@elettra, Basovizza Area Science Park, 34149, Trieste, Italy 4 CNR-IMIP, Monterotondo, Roma, Italy Keywords: synchrotron radiation, hydrogen migration, photodissociation, isoxazole, pyridine * twasowicz@mif.pg.gda.pl Absorption of radiation by hydrocarbon molecules can initiate their isomerization that usually provokes extensive deformation of molecular structure and reorganization of chemical bonds. In this rearrangement, hydrogen migration plays an important role, because a hydrogen atom or proton migrates from one site to another within a molecule [1] what may lead to opening of new reaction channels, frequently including dissociation [2-5]. The hydrogen movement occurs typically on a femtosecond time scale [3] and is faster than the molecular bond breaking in dissociation. It can therefore control chemical-bond-breaking and new bondforming processes in the biological radiation damage [5], combustion [6], or catalytic studies [7]. In this context, the five and six-membered heterocyclic hydrocarbons are ideal candidates to characterize the hydrogen migration mechanisms in their dissociation. Studies of these fundamental molecular processes are important, especially from the viewpoint of the DNA helix damage by the ionizing radiation. In particular, the five-membered ring of isoxazole molecule (Figure 1) may be discerned in the deoxyribose sugar of DNA. On the other hand, pyridine, the six-membered heterocyclic molecule (Figure 2), may be recognized in the nucleic bases, adenine and guanine. In the present study, the H atom migration was observed in the photodissociation processes of the isoxazole and pyridine molecules in the gas-phase, applying the photon-induced fluorescence spectroscopy (PIFS) [8]. The measured fluorescence emission spectra revealed the excited NH(A 3 Π) radicals detected by observation of their A 3 Π X 3 Σ bands (Figure 1) together with emission from the CH, CN and H excited dissociation fragments [9, 10]. Neither isoxazole nor pyridine molecules contain structural units built on NH group. Thus, observation of the NH(A 3 Π X 3 Σ ) fluorescence gives a clear evidence of the hydrogen migration prior to the photodissociation. 54

65 molecular ring and breakup of the molecular chain with formation of several excited fragmentation products. Figure 1. Emission spectrum of the isoxazole molecules showing the NH(A 3 Π X 3 Σ ) bands. In the studies of the photodissociation of isoxazole molecule we have performed the density functional and ab initio quantum chemical calculations [5] to propose the mechanism of hydrogen relocation and formation of the NH fragment: The photon energy dependences of the measured fragmentation yields show that the highly excited states, the super-excited states, of the target molecules produced in the photon absorption are intermediate states in fragmentation. The fluorescence yields of the excited NH(A 3 Π) and H(n=5) fragments measured in pyridine in the ev region (Figure 2) show pronounced excitation bands that rise at about 10 ev above the first ionization potential of pyridine (9.26 ev). The dissociation of the super-excited states proceeds by opening of the Figure 2. The NH(A 3 Π) and H(n=5) fragmentation yields obtained in the ev photon energy range. Acknowledgments: This work was in part financially supported under the CALIPSO contract. [1] H. F. Schaefer III, Acc. Chem. Res. 12 (1979) 288. [2] K. M. Morgan et al., J. Org. Chem. 66 (2001) [3] T. Osipov et al., Phys. Rev. Lett. 90 (2003) [4] Y. H. Jiang et al., Phys. Rev. Lett. 105 (2010) [5] M. Zubek et al., J. Chem. Phys. 141 (2014) [6] A. Ratkiewicz, Reac. Kinet. Mech. Cat. 108 (2013) 545. [7] D. R. Killelea et al., Science 319 (2008) 790. [8] T. J. Wasowicz et al., Phys. Rev. A 83 (2011) [9] T. J. Wasowicz et al., J. Phys. B At. Mol. Opt. Phys. 45 (2012) [10] T. J. Wasowicz et al., J. Phys. B At. Mol. Opt. Phys. 47 (2014)

66 P-20 Local electronic and crystal structures of FeTe doped with cobalt Our preliminary results shall be presented which indicate that the cobalt and iron positions cannot be described by only two (IP or OOP) possible locations, which is in agreement with earlier Mossbauer studies [6]. K. Żebrowska 1 *, M. Bagińska 1, M. Wojdyła 1, E. Salas-Colera 2, P. Zajdel 1** 1 Institute of Physics, University of Silesia, ul. Universytecka 4, Katowice, Poland 2 SpLine CRG, European Synchrotron Radiation Facility, CS40220, F Grenoble Cedex, France Keywords: XAFS, iron telluride, cobalt * kasia20075@onet.eu ** pawel.zajdel@us.edu.pl Due to inherent phase separation, it has been so far impossible to grow ideally stoichiometric (1:1) tetragonal (P4/nmm) iron telluride. The excess iron ions are located in the inter-planar positions and usually represented as a fraction x in a general formula Fe 1+x Te [1], where x ranges from about 4% to 17%. The additional iron has been found to negatively correlate with the level of anion site doping and subsequently with hindering the superconductivity (SC), for example in the Fe(Te,Se,S) series [2], where SC can be induced by doping with selenium or small amounts of sulfur. In our work, we attempted to create and investigate compounds electronically equivalent to variable iron stoichometry by substituting Fe with different transition metals [3]. Here we report our results for single crystals of FeTe doped with cobalt. Samples several millimeter in size were grown by solidification from melt method in the substitution range x=0.01 to 0.1. The incorporation of dopant into host was confirmed by WDS-SEM and observed trends in lattice parameters obtained from single crystal diffraction. However, it is not clear if Co is located in in-plane (IP) or out-of-plane (OOP) positions See Fig. 1 due to low level of doping and weak X-ray contrast between Co and Fe. In order to gain new insight into the problem we have performed Fe K, Co K and Te L edge XAFS studies on ESRF CRG SpLine [4] and MAXLAB-II I811 [5] beamlines. Figure 1. Possible locations of additional cobalt ions (a) inplane, (b) out-of-plane. Acknowledgments: This work is supported by the Polish National Science Centre grant No 2011/01/B/ST3/ The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ ) CALIPSO under grant agreement nº We would like to help N. Torapava for help during MAXLAB experiment. [1] W. Bao, Y. Qiu, Q. Huang, M. A. Green, P. Zajdel, M. R. Fitzsimmons, M. Zhernenkov, M. Fang, B. Qian, E. K. Vehstedt, J. Yang, H. M. Pham, L. Spinu, Z. Q. Mao Phys. Rev. Lett. 102 (2009) [2] P. Zajdel, Ping-Yen Hsieh, E. E. Rodriguez, N. P. Butch, J. D. Magill, J. P. Paglione, P. Zavalij, M. R. Suchomel, M. A. Green J. Am. Chem. Soc., 132 (2010) [3] I. Kruk, P. Zajdel, Journal of Crystal Crowth, 401(1) (2014) 608. [4] G.R. Castro, Journal of Synchrotron Radiation, 5 (1998) 657. [5] T.M. Grehk, P. O. Nilsson, Nucl. Instr. and Meth. in Phys. Res. A 635 (2001) 467. [6] A. Błachowski, K. Ruebenbauer, P. Zajdel, E. E. Rodriguez, M. A. Green, J. Phys.: Condens. Matter 24 (2012)

67 [7] P-21 Two step transition and suppression of monoclinic distortion in FeTe doped with nickel M. Bagińska 1 *, M. Wojdyła 1, K Żebrowska 1, I. -L. Liu 2,3, N. P. Butch 2,3, P. Zajdel 1** 1 Institute of Physics, University of Silesia, ul. Universytecka 4, Katowice. Poland 2 NIST Center for Neutron Research, Gaithersburg, MD Center for Nanophysics and Advanced Materials, Dept. of Physics, University of Maryland, College Park, MD Keywords: XAFS, iron telluride, nickel * monika.b0504@gmail.com ** pawel.zajdel@us.edu.pl Here we report our preliminary results of low temperature powder XRD performed on ground single crystals of FeTe doped with nickel, which reveals splitting and suppression of the structural phase transition in nickel doped system. The low temperature high resolution X-Ray diffraction (HRPD) studies have been carried out at ESRF CRG SpLine [5] beamline. The evolution of structural transition was followed by monitoring (112)t, (200)t peaks of the tetragonal unit cell. Reflection (112)t is sensitive only to monoclinic distortion and splits into (1-12)m and (112)m, whereas (200)t splits into (200) and (020) in both monoclinic and orthorhombic cells. Sample with 1% doping (Figure 1) revealed only small decrease of the transition temperature to 60K without removing the monoclinic distortion. On the other hand, doping with 5% of nickel showed significant lowering of the transition temperature to 30 K and almost complete suppression of monoclinic distortion. FeTe is a non-superconducting member of 11 family of iron based superconductors [1]. It has been found to become superconducting (SC) upon doping with sulfur or selenium [1,2], which is precursored by disappearance of the low temperature monoclinic (or orthorhombic) distortion of the tetragonal lattice. The other parameter critical for the SC is the amount of the interstitial iron [1,2], which we want to control by doping with nickel. Our preliminary low temperature laboratory XRD on Cr and Ni [3] series did not reveal any structural deformation upon cooling, which was a very promising result. Unfortunately, high resolution neutron powder diffraction carried at the NIST Center for Neutron Research revealed that the distortion is still present albeit gradually suppressed upon doping in Cr series [4]. Figure 2. Splitting of temperatures of monoclinic and orthorhombic transitions in Fe1.09Ni0.01Te. Figure 1. Monoclinic distorsion in Fe1.09Ni0.01Te seen by splitting of (112) and (220) peaks of the tetragonal cell. Acknowledgments: This work is supported by the Polish National Science Centre grant No 2011/01/B/ST3/ We would like to help Drs Castro and Salas-Colera for help during ESRF experiment. [1] Wei Bao, Y. Qiu, Q. Huang, M. A. Green, P. Zajdel, M. R. Fitzsimmons, M. Zhernenkov, M. Fang, B. Qian, E.K. Vehstedt, J. Yang, H. M. Pham, L. Spinu, Z. Q. Mao Phys. Rev. Lett. 102 (2009) [2] P. Zajdel, Ping-Yen Hsieh, E. E. Rodriguez, N. P. Butch, J. D. Magill, J. P. Paglione, P. Zavalij, M. R. Suchomel, M. A. Green J. Am. Chem. Soc., 132 (2010) [3] P. Zajdel, M. Zubko, J. Kusz, M. A. Green, Cryst. Res. Technol., 45(12) (2010) [4] I. Kruk, P. Zajdel, Journal of Crystal Growth, 401(1) (2014) 608. [5] G. R. Castro, Journal of Synchrotron Radiation, 5 (1998)

68 P-22 Local electronic and crystal structures of FeTe doped with nickel were later accompanied by measurements of Fe K and Te L absorption. M. Wojdyła 1*, K Żebrowska 1, M. Bagińska 1, E. Salas- Colera 2, P. Zajdel 1** 1 Institute of Physics, University of Silesia, ul. Universytecka 4, Katowice. Poland 2 SpLine CRG, European Synchrotron Radiation Facility, CS40220, F Grenoble Cedex, France Keywords: XAFS, iron telluride, nickel * martyna.wojdyla02@wp.pl ** pawel.zajdel@us.edu.pl Tetragonal (P4/nmm) iron telluride is known to possess natural non-stoichiometry, usually represented as a fraction x in a general formula Fe 1+x Te [1]. The excess iron ions are located in the inter-planar positions and their content x ranges from about 4% to 17%. Due to inherent phase separation, it has been so far impossible to grow ideally stoichiometric (1:1) FeTe The additional iron has been found to negatively correlate with the level of anion site doping and subsequently with hindering the superconductivity (SC), for example in the Fe(Te,Se,S) series [2], where SC can be induced by doping with selenium or small amounts of sulfur. Here we report our results for single crystals of FeTe doped with nickel, which is follow up on our ealier work [3]. Single crystal several millimeter in size were grown by solidification from melt method in the substitution range x = 0.01 to 0.1. The incorporation of dopant into host was confirmed by WDS-SEM and observed trends in lattice parameters obtained from single crystal diffraction. However, the SXRD study has not been decisive in location of nickel due to low level of doping and weak X-Ray contrast between Ni and Fe. There are two main locations of cations in the FeTe lattice. An inplane (IP) position, which is in the centre of FeTe 4 tetrahedron and out-of-plane (OOP) site, which is located over the Te plane See Fig. 1. In order to investigate a local environment around nickel we have Ni K XAFS studies on ESRF CRG SpLine [4] and MAXLAB-II I811 [5] beamlines. They Figure 1. Possible locations of additional nickel ions (a) inplane, (b) out-of-plane. Our preliminary results shall be presented, which indicate that the local crystallographic postions of nickel cannot be described by only two (IP or OOP) components, which is in agreement with many sites suggested earlier by Mössbauer studies [6]. Acknowledgments: This work is supported by the Polish National Science Centre grant No 2011/01/B/ST3/ The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ ) CALIPSO under grant agreement nº We would like to help N. Torapava for help during MAXLAB experiment. [1] W. Bao, Y. Qiu, Q. Huang, M. A. Green, P. Zajdel, M. R. Fitzsimmons, M. Zhernenkov, M. Fang, B. Qian, E.K. Vehstedt, J. Yang, H. M. Pham, L. Spinu, Z.Q. Mao Phys. Rev. Lett. 102 (2009) [2] P. Zajdel, Ping-Yen Hsieh, E. E. Rodriguez, N. P. Butch, J. D. Magill, J. P. Paglione, P. Zavalij, M. R. Suchomel, M. A. Green J. Am. Chem. Soc., 132 (2010) [3] I. Kruk, P. Zajdel, Journal of Crystal Crowth, 401 (2014) 608. [4] G. R. Castro, Journal of Synchrotron Radiation, 5 (1998) 657. [5] T.M. Grehk and P. O. Nilsson, Nucl. Instr. and Meth. in Phys. Res. A 635 (2001) 467. [6] A. Błachowski, K. Ruebenbauer, P. Zajdel, E. E. Rodriguez and M. A. Green, J. Phys.: Condens. Matter 24 (2012)

69 P-23 Li 0.95 Mn 2.05 O 4 under high pressure and at elevated temperature in DAC P. Piszora 1 *, J. Darul 1, C. Popescu 2, F. Fauth 2 1 Department of Materials Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, Poznań, Poland 2 CELLS-ALBA Synchrotron Light Source, Cerdanyola del Valles, Barcelona, Spain methanol ethanol mixture) and quasi-hydrostatically up to 10 GPa with a small maximum of nonhydrostaticity at 6 GPa [4]. Gold has been chosen as a pressure standard because of its moderate compressibility, chemical inertness, and large X-ray scattering power [5]. A small lump of gold with a purity of (four nines fine) and an average particle size of 30 µm was put in the hole of a rhenium gasket. Keywords: high pressure, high temperature, lithium-manganese spinel * pawel@amu.edu.pl A displacive crystal distortion to lower symmetry that cooperatively removes a localized-electron orbital degeneracy so as to leave the atoms in the centre of symmetry of their distorted sites has been observed in many manganese oxides. Moreover, strong Jahn-Teller electron-phonon coupling has been proposed as the crucial component which localizes the e g electrons as polarons. High pressure and high temperature are a means to tune such an interplay between lattice and electronic degrees of freedom in the lithium manganese spinel [1,2]. The Li 0.95 Mn 2.05 O 4 spinel sample was obtained from the appropriate amounts of thoroughly mixed powders of -Mn 2 O 3 and Li 2 CO 3 (99.0% Merck) by thermal treatment in air at 1048 K. After heating, the specimen was quenched rapidly in solid CO 2. Structural analyses showed the expected stoichiometry of the obtained powder and confirmed that no spurious phases were present. The structural properties of Li 0.95 Mn 2.05 O 4 under pressure and at elevated temperature were studied up to 13 GPa by X-ray powder diffraction at the MSPD-BL04 beamline [3] of the ALBA Synchrotron Light Source using monochromatic radiation ( = Å). Diffraction patterns were recorded on image plates and then integrated [8] to yield intensity vs 2 diagrams. For HP/HT experiments, sample was loaded in the 140-μm-diameter hole of an rhenium gasket inside a membrane-type diamond anvil cell (DAC) with a polydimethyl-siloxane oil of type Rhodorsil 47V1000 (VCR) as the pressure transmitting medium, which behaves hydrostatically up to 3 GPa (similar to the 4 : 1 Figure 1. Pressure-induced evolution of XRD pattern. Li 0.95 Mn 2.05 O 4 was studied by synchrotron X-ray diffraction isothermally at ambient temperature and at 107 C under pressures up to 12 GPa. Usually the cooperative Jahn Teller (JT) distortion is continuously reduced with increasing pressure. However, we obtained a strong indication that the JT effect and the concomitant orbital order are induced with pressure even if in the initial sample the cooperative Jahn Teller distortion has been suppressed with temperature. Acknowledgments: These experiments were performed at the MSPD-BL04 beamline at ALBA Synchrotron with the collaboration of ALBA staff. [1] N. Ishizawa, K. Tateishi, S. Oishi, S. Kishimoto, Am. Mineral. 99 (2014) [2] J. Darul, C. Lathe, P. Piszora, R. Soc. Chem. Adv. 4 (2014) [3] F. Fauth, I. Peral, C. Popescu, M. Knapp, Powder Diffr. 28 (2013) S360. [4] S. Klotz, J. C. Chervin, P. Munsch, G. Le Marchand, J. Phys. D: Appl. Phys. 42 (2009) [5] K. Takemura, A. Dewaele, Phys. Rev. B 78 (2008)

70 P-24 The dynamics of micellization of gemini imidazolium surfactants studied by NMR, FT-IR and SR-SAXS K, Szutkowski, Z. Pietralik, M. Kozak* Department of MaclomolecularPhysics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznań, Poland Keywords: synchrotron radiation, small angle X-ray scattering, cmc, dicationic surfactants * Gemini surfactants, also known as dimeric or dicationic surfactants are recently studied as components of drug delivery systems, especially for gene therapy [1,2]. This group of surfactants has cmc (critical micellization concentration) much lower than that of a monomeric surfactants with equivalent aliphatic chain length [3]. The aim of this study was the characterization of structural parameters and cmc values characterizing the solutions of selected gemini surfactants (3,3 -[α,ω- (dioxaalkane)] bis(1-alkylimidazolium) chlorides). The critical micellization concentration for imidazolium gemini surfactans with spacer widths ranging from 2 to 8 methylene groups were obtained. At the first stage the concentrated solutions of gemini surfactants (over cmc) were characterized by the use of small angle scattering of synchrotron radiation technique (SR-SAXS). High resolution DOSY NMR revealed some unusual aggregation behavior, related to high polydispersity of surfactant aggregates for the concentrations higher than CMC. Obtained cmc's values ranged from 0.01 mm up to 1 mm. Furthermore ph dependence was observed as a result of electrostatic interaction between imidazolium ions. The complex dynamics of spacer was confirmed by FT-IR studies. Additionally selected systems were characterized by FFC spectroscopy. Acknowledgments: This research project has been financed by the funds from the National Science Centre (Poland) granted on the basis of decision no. DEC-2011/01/B/ST5/ [1] H. Yin, R.L. Kanasty, A. A. Eltoukhy, A. J. Vegas, J. R. Dorkin, D. G. Anderson, Nature Reviews Genetics 15 (2014) 541. [2] P. Luciani, C. Bombelli, M. Colone, L. Giansanti, S. Ryhaenen, V. M. J. Saily, G. Mancini, P. K. J. Kinnunen Biomacromolecules 8 (2007) [3] R. Zana, Advances in Colloid and Interface Science 97 (2002)

71 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) Regular Contribution Działalność Naukowa Pracowni Spektroskopii Optycznej Półprzewodników Instytutu Fizyki Uniwersytetu Jagiellońskiego. Udział w badaniach z zastosowaniem promieniowania synchrotronowego A. Kisiel* Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. prof. St. Łojasiewicza 11, Kraków * andrzej.kisiel@uj.edu.pl Wprowadzenie Odbudowanie fizyki doświadczalnej w Uniwersytecie Jagiellońskim po zniszczeniach II wojny światowej było priorytetem prof. H. Niewodniczańskiego, który po objęciu w roku 1946 II Katedry Fizyki Doświadczalnej zorganizował i istotnie ożywił działalność naukową. 1 Jako uznany w świecie naukowym badacz w zakresie spektroskopii atomowej, w kierowanej Katedrze Fizyki Doświadczalnej (KFD), przemianowanej w połowie lat pięćdziesiątych ubiegłego stulecia na Zakład Fizyki Doświadczalnej (ZFD), proponował zwykle nowo przyjętym współpracownikom podjęcie badań naukowych w dziedzinie spektroskopii atomowej. Autor tego artykułu, przyjęty w roku 1953 na asystenturę w KFD, również otrzymał taką propozycję. Dotyczyła ona podjęcia badań stosunków natężeń w multipletach linii widmowych wodoropodobnych jonów aluminium i krzemu tzn. jonów z jednym elektronem walencyjnym. jako podstawowe materiały półprzewodnikowe do wytwarzania tranzystorów. Zainteresowanie się spektroskopią optyczną półprzewodników było naturalną konsekwencją doświadczenia nabytego w zakończonych badaniach w zakresie spektroskopii atomowej. Prof. H. Niewodniczański dostrzegł również przyszłościowe perspektywy badawcze spektroskopii optycznej półprzewodników. Pomimo że do tego czasu w Zakładzie Fizyki Doświadczalnej były głównie prowadzone badania w zakresie spektroskopii atomowej, prof. H. Niewodniczański zaakceptował podjęcie nowego kierunku badań spektroskopowych i aktywnie wspierał ich rozwój aż do swojej śmierci w grudniu 1968 roku. Gorąca zachęta do podjęcia tych badań nadeszła również od wysoko cenionych specjalistów w zakresie fizyki półprzewodników profesorów Wiesława Wardzyńskiego z Instytutu Fizyki Doświadczalnej Uniwersytetu Warszawskiego Rysunek 1. Profesor H.Niewodniczański. Po zakończeniu przewidywanego programu badań rozprawą doktorską i publikowanymi artykułami 2, szczególne zainteresowanie naukowe autora artykułu wzbudzało, rozpoczęte w Europie i USA w połowie lat pięćdziesiątych ubiegłego wieku, eksperymentalne analizowanie struktury elektronowej pasma walencyjnego i pasma przewodnictwa ciał stałych przy użyciu metod spektroskopii optycznej 3. Badania te dostarczały fundamentalne informacje o strukturze elektronowej ciał stałych. Okazały się szczególnie cenne przy zbieraniu informacji o strukturze elektronowej pasm walencyjnego i przewodnictwa germanu 4 i krzemu 5, robiących wówczas oszołamiącą karierę w elektronice, 61 Rysunek 2. Wspólny spacer po Czantorii w czasie Międzynarodowej Szkoły Fizyki Półprzewodników w Jaszowcu. Prof. W. Wardzyński (drugi z lewej) i prof. W. Giriat w środku grupy uczestników Szkoły. i Witolda Giriata z Instytutu Fizyki PAN w Warszawie. Prof. W. Giriat, jako wybitny specjalista w zakresie technologii wytwarzania monokryształów związków półprzewodnikowych, zaoferował stałe dostarczanie, niezbędnych do badań, bardzo wysokiej jakości monokrystalicznych materiałów półprzewodnikowych. Dało to podwaliny wieloletniej, wzajemnej bardzo efektywnej współpracy. Wykorzystując wymienione powyżej sprzyjające okoliczności, w roku 1965 w Zakładzie Fizyki Doświadczalnej IF UJ powstała Pracownia Spektroskopii Optycznej Półprzewodników (PSOP).

72 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) Badania eksperymentalne w Pracowni Spektroskopii Optycznej Półprzewodników (PSOP) Działalność badawczą PSOP zapoczątkowały próby przystosowywania próżniowego spektrografu z pryzmatem i soczewkami z krystalicznego fluorytu, używanego we wcześniejszych badaniach widm liniowych Si IV 6 do badań współczynników absorpcji i odbicia światła półprzewodników. Spektrograf ten został zakupiony w Niemczech przez profesora H. Niewodniczańskiego w roku 1946 za środki otrzymane od Niemiec w ramach reparacji wojennych wypłacanych za mienie zrabowane w czasie II wojny światowej. Odpowiednie przystosowanie tego spektrografu do badań optycznych półprzewodników napotkało jednakże na szereg poważnych trudności technicznych, które ostatecznie przesądziły o rezygnacji z adaptacji spektrografu fluorytowego do dalszych badań i o konieczności podjęcia starań o zakup odpowiedniego monochromatora na obszar próżniowego nadfioletu. Równocześnie z pracami nad adaptacją spektrografu był budowany jednowiązkowy odbiciomierz fotoelektryczny na obszar widzialny i bliskiego nadfioletu (od 600 do 200 nm) co odpowiada energii promieniowania od ok. 1,8 6 ev. Uruchomiony odbiciomierz działał w systemie wiązki białej, tzn. że skupiona na próbce biała wiązka światła ze źródła po odbiciu od próbki była skupiana na szczelinie wejściowej monochromatora analizującego rozkład widmowy wiązki. Natężenie wiązki było mierzone przez fotopowielacz umieszczony na szczelinie wyjściowej monochromatora i rejestrowane po wzmocnieniu przez fazoczuły elektroniczny układ detekcyjny. Przy użyciu tego układu pomiarowego zostały uzyskane i opublikowane w roku 1969 pierwsze wyniki badań dotyczące analizy widm odbicia światła dla kilku monokrystalicznych potrójnych związków półprzewodnikowych CdHgTe, wytworzonych przez Roberta Gałązkę w laboratorium technologicznym Instytutu Fizyki Doświadczalnej Uniwersytetu Warszawskiego [4, 5] 7. Przy użyciu tego odbiciomierza fotoelektrycznego kontynuowano również dalsze badania fundamentalnego odbicia światła dla monokrystalicznych roztworów stałych Cd x Hg 1-x Te [5, 7] i Zn x Cd 1-x Te [6]. Rozwijane w PSOP badania widm odbicia światła półprzewodników stały się motorem do sformułowania w październiku 1969 roku wniosku Instytutu Fizyki UJ o włączenie do Centralnego Planu 5-letniego badań naukowych i rozwoju technicznego na lata , badań optycznych ciała stałego w zakresie próżniowego nadfioletu 6 10 ev, w oparciu o posiadaną bazę aparaturową oraz budowane konwencjonalne wodorowe i helowe źródła promieniowania elektromagnetycznego świecące w obszarze próżniowego nadfioletu. Aby sprostać tym planom PSOP została wzmocniona, przyjętymi na asystentury do ZFD, mgr Martę Zimnal i mgr Barbarę Pukowską. Na przełomie roku 1970 i 1971 autor artykułu, jako stypendysta Rządu Republiki Włoch, odbył półroczny staż w Instytucie Fizyki Uniwersytetu Rzymskiego La Sapienza w grupie teoretycznej prof. Franco Bassaniego, wybitnego specjalisty w skali światowej 62 w zakresie obliczeń teoretycznych struktury elektronowej krystalicznych ciał stałych. W czasie tego pobytu powstała publikacja, przygotowana wspólnie z drugim stypendystą dr Peterem M. Lee z Uniwersytetu w Lancaster (GB). Praca ta dotyczyła teoretycznego opisu istotnej roli poprawek relatywistycznych przy powstawaniu przejścia od prostej do odwróconej przerwy wzbronionej w strukturze elektronowej potrójnych związków Cd 1-x Hg x Te [10]. Ta publikacja i wcześniejsze prace eksperymentalne opisujące strukturę elektronową roztworów stałych Cd x Hg 1-x Te [5, 7] i Zn x Cd 1-x Te [6] złożyły się na rozprawę habilitacyjną autora artykułu [8, 9]. W trakcie pobytu na stypendium Prof. F. Bassani zaproponował by prowadzone w PSOP ZFD w Krakowie, eksperymentalne badania fundamentalnego odbicia półprzewodników w zakresie energii 1,8 6 ev, rozszerzyć na zakres próżniowego nadfioletu Rysunek 3. Prof. G.F. Bassani, inicjator współpracy włoskopolskiej. ( ev) z użyciem promieniowania synchrotronowego z 1,1 GeV synchrotronu usytuowanego w INFN (Istituto Nazionale di Fisica Nucleare) we Frascati. Badania odbicia światła półprzewodników miały być prowadzone we współpracy z kierowaną przez prof. F. Bassaniego grupą Solidi Roma 8, posiadającą bezpośredni dostęp do wykorzystujących promieniowanie synchrotronowe dwu optycznych linii pomiarowych we Frascati. Podjęcie wspólnych włoskopolskich eksperymentalnych badań optycznych rozszerzało i nakładało wyższe wymagania merytoryczne na rozpoczęte wcześniej w PSOP badania w zakresie spektroskopii optycznej półprzewodników. Aby sprostać tym wymaganiom w kolejnych latach współpracy doskonalono technikę pomiaru fundamentalnego odbicia światła i szczegółowo analizowano czynniki fizyczne (naprężenia wewnętrzne, wpływ obróbki mechanicznej i trawienia na chropwatość powierzchni) badanych materiałów. Włączenie się do badań z zastosowaniem promieniowania synchrotronowego miało kolosalne znaczenie dla rozwoju, opisanej szczegółowiej w paragrafie 4, aktywności naukowej PSOP.

73 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) Po objęciu przez autora artykułu w październiku 1973 roku kierownictwa Zakładu Fizyki Ogólnej (ZFO), PSOP została automatycznie przeniesiona z ZFD do ZFO wraz ze współpracownikami mgr Jolantą Dydecką, mgr Barbarą Pukowską i mgr Martą Zimnal oraz technikiem elektronikiem Romualdem Samsonem. (np. CuInS 2 ) analizowane pod kątem zastosowań fotowoltaicznych. Rysunek 4. Prof. W. Giriat i autor artykułu w przerwie obrad Międzynarodowej Szkoły Fizyki Półprzewodników w Jaszowcu. Fundamentalne odbicie światła półprzewodników jest niezwykle czułe na jakość badanych monokryształów i stan powierzchni odbijającej, w związku z tym bez dobrych, wszechstronnie atestowanych materiałów półprzewodnikowych dostarczonych przez renomowane pracownie technologiczne nie można było myśleć o wiarygodnych badaniach. Ze względu na bardzo wysokie koszty uruchomienia technologii wytwarzania dobrej jakości atestowanych monokryształów i cienkich warstw materiałów półprzewodnikowych potrzebnych do badań, została nawiązana przez PSOP nieformalna, obopólnie korzystna współpraca z kilkoma krajowymi i zagranicznymi laboratoriami technologicznymi. PSOP współpracowała z laboratoriami technologicznymi Instytutu Fizyki Doświadczalnej Uniwersytetu Warszawskiego (prof. R.R. Gałązka, prof. W. Giriat)), Instytutu Fizyki PAN w Warszawie (prof. W. Giriat i A. Mycielski), Instytutu Tele-Radiotechnicznego w Warszawie (doc. S. Ignatowicz), Instytutu Fizyki Politechniki Wrocławskiej (prof. J. Pawlikowski), Zakładu Fizyki PAN w Zabrzu (doc. L. Żdanowicz) i Instytutu Fizyki Technicznej Wojskowej Akademii Technicznej w Warszawie (prof. J. Żmija i M. Demianiuk), a także z dr R.D. Tomlinsonem z Departamentu Inżynierii Elektrycznej i Elektroniki (Department of Electronic and Electrical Engineering) Uniwersytetu w Salfort (Wielka Brytania), prof. J.K. Viscacasem z Instytutu Fizyki Uniwersytetu w Wilnie i prof. W.J. Potykiewiczem z Instytutu Fizyki Uniwersytetu Kijowskiego. Przez wiele lat kontynuowano również współpracę z prof. W. Giriatem po jego emigracji do Wenezueli, gdzie w Instituto Venezolano de Ivestigationes Cientificas, Centro de Fisica (IVIC) w Caracas wytwarzał obok monokryształów związków półprzewodnikowych grupy II-VI z metalami przejściowymi również bardzo wysokiej jakości monokrystaliczne związki typu II III 2 VI 4 (np. CdIn 2 S 4, ZnIn 2 S 4, ZnGa 2 Se 4, CdGa 2 S 4 ) i I III VI 2 63 Rysunek 5. Obrady Międzynarodowej Konferencji Cienkich Warstw w Budapeszcie. W pierwszym rzędzie trzeci od lewej prof. J.K. Viscacas, w drugim rzędzie trzeci od lewej autor artykułu, obok doc. S. Ignatowicza. Po nawiązaniu współpracy naukowej z kilkoma pracowniami technologicznymi były prowadzone badania fundamentalnego odbicia dla cienkich warstw ZnTe i CdHgTe [14, 17, 21, 22, 25, 26, 43] oraz cienkich warstw Zn 2 As 3 [13, 18]. Nowo zaangażowani wspólpracownicy Marek Podgórny i Andrzej Rodzik prowadzili badania fundamentalnego odbicia światła w funkcji składu i temperatury monokryształów roztworów stałych CdHgTe [19, 20, 23] a Katarzyna Karnicka-Mościcka dla cienkich warstw Cd 3 As 2 [27, 37, 64, 65, 72]. Wszystkie te badania były prowadzone przy użyciu odbiciomierza fotoelektrycznego w systemie wiązki białej, w którym uciążliwą technicznie obróbkę danych pomiarowych zastąpiono układem automatycznej fazoczułej rejestracji danych [15]. Układ ten znacznie podwyższał dokładność pomiarów i szybkość rejestracji rezultatów doświadczalnych. Realizując cele naukowe PSOP zapowiadane w projekcie współpracy z grupą Solidi Roma, dotyczące prowadzenia komplementarnych badań całego obszaru fundamentalnego odbicia półprzewodników, w roku 1975 został zakupiony przez IF UJ dla PSOP 1-metrowy siatkowy monochromator próżniowy firmy Hilger & Watts E766. Na bazie tego monochromatora został zbudowany i uruchomiony dwuwiązkowy odbiciomierz na zakres próżniowego nadfioletu od 5 11 ev z automatyczną rejestracją danych [40]. Z pomocą tego spektrometru przeprowadzono badania wpływu temperatury na współczynniki absorpcji i odbicia dla CdF 2 [47,57] oraz analizę fundamentalnego odbicia dla monokryształów Cd x Hg 1-x Te [56,59] i ZnTe [60]. W celu udoskonalenia pomiarów fundamentalnego odbicia półprzewodników w zakresie energii 1,5 6 evzbudowano w PSOP kilka wersji dwuwiązkowego odbiciomierza fotoelektrycznego z automatyczną, fazoczułą rejestracją danych współpracującą on line z komputerem [73, 95]. W skonstruowanych odbiciomierzach wiązka światła monochromatycznego była dzielona na dwie części: jedna z nich oświetlała badaną próbkę i odbita od niej padała na fotopowielacz mierzący jej natężenie, druga

74 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) część, jako wiązka odniesienia, za pomocą układu luster była kierowana wprost na drugi fotopowielacz. Rysunek 6. A. Rodzik przy dwuwiązkowym odbiciomierzu z automatyczną rejestracją danych. W takim układzie był możliwy pomiar współczynnika odbicia (lub absorpcji), z wyeliminowaniem efektów związanych z podświetlaniem wiązką białą badanych materiałów oraz fluktuacji natężenia padającego światła. Budowane zestawy pomiarowe odznaczały się bardzo wysoką czułością i dokładnością pomiaru, przewyższającą czułość i zdolność rozdzielczą spektrometrów komercyjnych produkowanych przez renomowane firmy zagraniczne w latach siedemdziesiątych i osiemdziesiątych ubiegłego wieku. Należy podkreślić, że powszechnie stosowane w spektroskopii optycznej do końca lat pięćdziesiątych ubiegłego wieku spektrografy z rejestracją widm optycznych na kliszy fotograficznej, w ciągu zaledwie dziesięciu lat, zostały zastąpione w laboratoriach naukowych przez monochromatory z fotoelektryczną rejestracją natężeń widm optycznych ( np. przy użyciu fotopowielaczy) i fazoczułych wzmacniaczy współpracjących on line z komputerem. Rozwój techniki pomiarowej w PSOP nadążył za tą rewolucyjną przebudową światowej techniki pomiarowej w spektroskopii optycznej. W latach zostały podjęte próby zwiększenia dokładności opisu struktury elektronowej badanych materiałów poprzez zastosowanie metod modulacyjnych w badaniach spektroskopowych [35, 52]. Jednakże ze względu na obecność dodatkowych charakterystycznych efektów w odbiciowych widmach modulacyjnych, nie rozwijano dalej tej metodyki i skierowano wszystkie wysiłki na uzyskanie jak najwyższej czułości i zdolności rozdzielczej w bezpośrednim pomiarze odbicia światła. Ze względu na bardzo silną zależność fundamentalnego odbicia od doskonałości struktury krystalicznej badanych materiałów oraz stopnia czystości i chropowatości powierzchni próbek, prowadzone badania dostarczały nie tylko podstawowe informacje o strukturze elektronowej materiałów, ale również wiedzę o niedoskonałościach i naprężeniach wewnętrznych struktury krystalicznej badanych materiałów a także o właściwościach powierzchni odbijającej. 64 Tak więc obok podstawowych badań struktury elektronowej pasm walencyjnego i przewodnictwa wielu związków półprzewodnikowych, wymagających eliminacji efektów zaburzających poprawny pomiar [13, 14, 16, 17, 18-23, 27, 30, 31, 37, 47, 56, 57, 59-61, 66, 72-74, 81], siłą rzeczy, rozwinęły się również diagnostyczne badania niedoskonałości struktury krystalicznej [25, 31, 38, 55, 58, 66, 67, 71, 81, 84] i naprężeń wewnętrznych w kryształach i polikrystalicznych cienkich warstwach [25, 45, 55, 58, 61, 62] oraz nierówności powierzchni odbijających [38, 41-46, 49-51, 65]. Badania wpływu nierówności powierzchni na widmo optyczne metali i półprzewodników znalazło zastosowanie jako nieniszcząca metoda diagnostyki powierzchni metalizowanego i niemetalizowanego kwarcu [41-44, 46, 49-51]. Metoda ta była opracowywana, w ramach programów węzłowych i resortowych, dla Instytutu Tele-Radiotechnicznego w Warszawie. W PSOP przybywało współpracowników. Razem z podstawowym składem osobowym: Ewą Czarnecką- Such, Barbarą Pukowską, Markiem Podgórnym, Andrzejem Rodzikiem, Markiem Turowskim i Martą Zimnal-Starnawską, w rozwoju badań uczestniczyli doktoranci: Barbara Oleś, Katarzyna Karnicka-Mościcka, Marek Czyżyk, Józef Oleszkiewicz, Dorota Dębowska, Jacek Goniakowski, Artur Hołda i Paweł Zajdel oraz spore grono magistrantów. Część doktorantów po uzyskaniu stopni doktora została zatrudniona na etatach w PSOP ZFO 9. Prowadzone badania dostarczały szereg nowych i interesujących rezultatów. Szeroko zakrojone badania struktury elektronowej półprzewodnikowych związków mieszanych Cd x Hg 1-x Te zostały nagrodzone w roku 1978 zespołową nagrodą Ministra Nauki i Szkolnictwa Wyższego i Techniki III stopnia 10. Marek Turowski po obronie doktorskiej w roku 1982 wyjechał na stypendium do Instytutu Fizyki w Uniwersytecie Neymegen (Holandia) a następnie do Departamentu Fizyki Uniwersytetu w Wisconcin (USA), gdzie pod kierunkiem prof. Giorgio Margaritondo brał udział w badaniach fotoemisji elektronowej krzemu oraz heterozłączy na orientowanych monokryształach GaAs z użyciem promieniowania synchrotronowego z synchrotronu w Wisconcin [87-93]. Niestety po powrocie do Polski z tego stażu naukowego zrezygnował z pracy w IF UJ i wyjechał na stałe do USA. W drugiej połowie lat siedemdziesiątych ubiegłego stulecia została zapoczątkowana również współpraca naukowa z Wilnem i Kijowem na bazie zawartych umów o współpracy bezpośredniej pomiędzy Uniwersytetami Jagiellońskim, Wileńskim i Kijowskim. Wizyty prof. J.K.Viscakasa i A. Żyndulisa z Uniwersytetu Wileńskiego oraz prof. W.J. Potykiewicza z Uniwersytetu Kijowskiego zaowocowały wspólnymi publikacjami [31,60]. Po przerwie natury politycznej, w latach dziewięćdziesiątych ożywiły się kontakty naukowe z Instytutem Fizyki Uniwersytetu Kijowskiego oraz zostały nawiązane kontakty naukowe z prof. V.I. Strikhą i H. Pieką oraz z dr P.W. Żukowskim z Instytutu Fizyki Uniwersytetu w Mińsku. Wynikiem współpracy A. Rodzika i E. Czarneckiej-Such na temat fizyko-

75 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) chemicznych własności powierzchni CdMnTe oraz własności dielektrycznych i optycznych Si implantowanego jonami były publikacje [167, 169, 173, 176, 189, 192]. Rysunek 7. Wizyta w Instytucie Radiofizycznym Uniwersytetu Kijowskiego. Od lewej E.V. Buzaneva, A. Rodzik i E. Czarnecka-Such. Ze względu na wspólne z PSOP zainteresowania badaniami z użyciem promieniowania synchrotronowego w roku 1996 dołączył do ZFO Marek Stankiewicz i utworzył Pracownię Spektroskopii Molekularnej (PSM). Przedmiotem jego badań były procesy i mechanizmy relaksacji prostych drobin tzn. badania fotodysocjacji molekularnej, foto-fragmentacji, fotoemisji elektronowej molekuł i fotojonizacji przy użyciu promieniowania synchrotronowego z synchrotronu SRS w Daresbury (Wielka Brytania) i synchrotronu MAX II (Szwecja). Rezultaty tych badań zostały opublikowane w kilkunastu artykułach [ , , 251, ]. W utworzonej Pracowni Spektroskopii Molekularnej ZFO, M. Stankiewicz obok badań z użyciem promieniowania synchrotronowego wykorzystał do badań fotodysocjacji drobin posiadany przez PSOP ZFO 1-metrowy monochromator próżniowy Hilger&Watts oraz laser Nd/YAG z 2 i 3 harmoniczną. Na bazie tych urządzeń został zbudowany analizator czasu przelotu z detektorem mikrokanalikowym i wielokanałowym przetwornikiem czas/cyfra o wysokiej zdolności rozdzielczej oraz komputerową akwizycją danych doświadczalnych. W budowie aparatury i badaniach uczestniczył doktorant Piotr Winiarczyk oraz magistranci. Istotnym czynnikiem działalności naukowej PSOP ZFD a następnie PSOP ZFO była współpraca naukowa rozwijana z Włochami, Republiką Federalną Niemiec, Wielką Brytanią, Szwecją i ZSSR. Szczególnie ścisła i długotrwała współpraca PSOP ułożyła się z Instytutem Fizyki, a następnie Departamentem Fizyki Wydziału Inżynierii Uniwersytetu Rzymskiego I La Sapienza i z Laboratorium Narodowym we Frascati (Laboratori Nazionali di Frascati (LNF)) przynależącym do Instytutu Narodowego Fizyki Jądrowej (Istituto Nazionale di Fisica Nucleare (INFN)). Ponadto przez szereg lat trwała współpraca z Departamentem Fizyki Uniwersytetu w Trento (od 1986 roku, umowa podpisana w roku 1989) oraz z Instytutem Fizyki Uniwersytetu 65 Rzymskiego II Tor Vergata (formalnie potwierdzona umową o współpracy bezpośredniej w roku 1993). Wczesna działalność naukowa PSOP została zaprezentowana w roku 1983 w artykule opublikowanym w czasopiśmie Optica Applicata [83]. Pełna działalność badawcza, wchodzących w skład Zakładu Fizyki Ogólnej, Pracowni Spektroskopii Optycznej Półprzewodników, Pracowni Spektroskopii Interferencyjnej i Pracowni Spektroskopii Molekularnej, została opisana w artykule zamieszczonym w roku 2014 na stronie internetowej IF UJ 11. Powstanie i działalność grupy teoretycznej PSOP Do właściwej interpretacji eksperymentalnych widm współczynników absorpcji i fundamentalnego odbicia światła niezbędne jest porównywanie ich z bardzo zaawansowanym opisem teoretycznym struktury elektronowej półprzewodników. W związku z tym w PSOP zaistniała potrzeba wykształcenia grupy teoretyków specjalizujących się w obliczeniach teoretycznych dotyczących struktury elektronowej półprzewodników i metali. Korzystając z licznych dyskusji ze współpracującymi z PSOP teoretykami prof. F. Bassanim i jego uczniem F. Casulą, współautorem wspólnej z autorem tego artykułu teoretycznej publikacji na temat struktury elektronowej Cd x Hg 1-x Te [35], M. Podgórny a następnie M. Czyżyk rozpoczęli samodzielne teoretyczne obliczenia struktury elektronowej CdTe i HgTe [53] oraz Cd x Hg 1-x Te [48], a także analizy poprawek w opisie potencjału miseczkowego stosowanego w obliczeniach struktury elektronowej [85]. W zadaniu tworzenia w PSOP wyspecjalizowanej grupy teoretyków szczególnie ważne wsparcie otrzymaliśmy od prof. Joachima Treutscha, kierownika Katedry Fizyki Teoretycznej Uniwersytetu w Dortmundzie 12. Prof. J. Treutsch, wybitny specjalista w badaniach teoretycznych struktury elektronowej ciał stałych, dzięki swym wpływom, ułatwił uzyskanie rocznego stypendium im. Aleksandra von Humboldta dla M. Czyżyka i dwuletniego stypendium dla M. Podgórnego oraz przyjął bezpośrednią opiekę nad obydwoma stypendystami. M. Podgórny opublikował wspólnie ze współpracownikami prof. M. Treuscha J. Pollmannem [111] i D. Wagnerem [112] bardzo cenne rezultaty naukowe dotyczące obliczeń struktury elektronowej roztworów stałych SiGe oraz strukturalnych i magnetycznych przejść fazowych w stopach metali przejściowych. W wyniku dalszych badań M. Podgórny opublikował kilka interesujących wyników teoretycznych na temat magnetyzmu wędrownego w ciałach stałych. Publikacje te stanowiły podstawę doskonałej dysertacji habilitacyjnej, wyjaśniającej nierozwiązany od końca dziewiętnastego wieku, problem bardzo niskiej rozszerzalności termicznej inwaru [115, ]. Przyjazna pomoc i zaangażowanie prof. J. Treuscha, przy wykształceniu dla PSOP dojrzałych naukowo młodych teoretyków, owocowała przez wiele lat. Z upływem czasu powstałą grupę teoretyczną wzmocnili: J. Goniakowski doktorant M. Podgórnego, ściśle współpracujący z nami R. Markowski, pracownik Zakładu Techniki Komputerowej, oraz doktoranci PSOP

76 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) ZFO J. Oleszkiewicz, A. Hołda i P. Zajdel, którzy opanowali biegle zaawansowane teoretyczne techniki obliczania struktury elektronowej półprzewodników. 129, 159, 141, 142, 155, 157, 158, 177, 198, 239, 240, ]. Rysunek 8. Spotkanie towarzyskie w domu M. Zimnal- Starnawskiej. Od lewej M. Podgórny, M. Czyżyk, F. Antonangeli i autor artykułu. W latach dziewięćdziesiątych ubiegłego wieku PSOP poniosła dotkliwe straty szczególnie wśród kolegów teoretyków. M. Podgórny bezpośrednio po habilitacji, oraz współpracujący z PSOP R. Markowski, zaraz po doktoracie, ulegli fascynacji niezwykłym rozwojem informatyki w USA i wyjechali tam na wieloletnie kontrakty, z których już nie wrócili do Polski. M.T. Czyżyk, z podobnych motywów, pozostał na stałe w Holandii. Poniesiony uszczerbek w gronie teoretyków w PSOP został częściowo uzupełniony przez Jerzego Koniora, wychowanka Zakładu Fizyki Statystycznej IF UJ i adiunkta w Instytucie Fizyki Wyższej Szkoły Pedagogicznej (obecnie Uniwersytetu) w Rzeszowie. Do roku 1989 głównym przedmiotem badań J. Koniora była mikroskopowa teoria płynów prostych, a badania prowadził we współpracy z prof. Czesławem Jędrzejkiem z IF UJ [134, 148]. Jeszcze przed powrotem do IF UJ w 1989 roku J. Konior rozpoczął badania teoretyczne w zakresie nadprzewodnictwa wysokotemperaturowego [135, 174, 191, 193, 209]. Badania te kontynuował m.in. podczas pobytu we Francji w Uniwersytecie Paris-Nord [149, 163, 164, 166, 210] oraz we współpracy z doktorantem P. Piekarzem [252, 258]. Za wkład do teorii układów silnie skorelowanych i nadprzewodnictwa wysokotemperaturowego został nagrodzony Nagrodą Ministra Edukacji Narodowej 13. Niedługo po zatrudnieniu w PSOP ZFO ukończył rozprawę habilitacyjną [238] i włączył się aktywnie do prowadzonych w PSOP teoretycznych badań struktury elektronowej półprzewodników [211]. Wspólnie z eksperymentatorami interpretował wyniki doświadczalne fundamentalnego odbicia oraz absorpcyjnej spektroskopii rentgenowskiej XANES i EXAFS [201, 214, 225, 264, 268, 269]. Poniesione straty personalne kompensowało również ponowne nawiązanie kilkuletniej współpracy na odległość z dr P.M. Lee teoretykiem z Uniwersytetu w Lancaster, dawnym współpracownikiem autora artykułu. Dzięki rozwojowi internetu współpraca ta zaowocowała wieloma wspólnymi wartościowymi publikacjami [128, 66 Rysunek 9. Wspólna herbata w sali seminaryjnej PSOP. Na zdjęciu W. Kwiatek (pierwszy od lewej), J. Oleszkiewicz, autor artykułu, E. Czarnecka-Such, B. Popiołek (sekretarka), P. Klocek (częściowo widoczny), M. Stankiewicz, M. Zimnal- Starnawska, J. Konior i R. Samson i A. Banaś. Udział PSOP w badaniach z użyciem promieniowania synchrotronowego Złożona wiosną 1971 roku przez prof. F. Bassaniego autorowi artykułu propozycja podjęcia współpracy polsko-włoskiej w zakresie wykorzystywania do badań w spektroskopii optycznej półprzewodników promieniowania synchrotronowego z 1,1 GeV synchrotronu usytuowanego w Frascati była nadzwyczaj cenna i dalekowzroczna. Proponowane badania rozszerzały horyzonty i istotnie modyfikowały programy badawcze PSOP. Jednakże doprowadzenie do faktycznej współpracy wymagało jeszcze szeregu ustaleń oraz kilku lat zabiegów organizacyjnych. W czasie kolejnej wizyty autora artykułu w Instytucie Fizyki Uniwersytetu Rzymskiego w roku 1972 i rewizytach w Krakowie w roku 1973 profesorów F. Bassaniego i G. Chiarottiego oraz dr A. Balzarottiego, został sformułowany na piśmie plan wspólnych badań, dotyczący analizy własności optycznych różnych związków półprzewodnikowych z użyciem promieniowania synchrotronowego. Plan ten przewidywał następujący podział zadań: ze strony polskiej: a) proponowanie tematyki z zakresu badania struktury elektronowej związków półprzewodnikowych, b) dostarczanie we współpracy z Instytutem Fizyki PAN w Warszawie wysokiej jakości monokrystalicznych związków półprzewodnikowych, c) prowadzenie komplementarnych badań współczynników odbicia i pochłaniania światła w zakresie energii promieniowania od 1,5 do 10,0 ev 14, oraz d) częściowe wsparcie teoretycznymi obliczeniami struktury elektronowej związków półprzewodnikowych; ze strony włoskiej: a) współpracę w ramach grupy Solidi Roma przez udostępnienie polskim współpracownikom czasu pracy na próżniowym spektrometrze wykorzystującym jako źródło światła promieniowanie synchrotronu elektronowego we Frascati w zakresie energii światła od 10 do 300 ev oraz b) współpracę w zakresie obliczeń teoretycznych struktury elektronowej związków półprzewodnikowych.

77 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) Opracowany przez PSOP ZFO i grupę Solidi Roma szczegółowy program badań w zakresie spektroskopii optycznej ciała stałego z wykorzystaniem promieniowania synchrotronowego był pierwszą tego typu inicjatywą w Polsce. Ściślejsze kontakty badawcze PSOP z grupą Solidi Roma nabrały tempa na przełomie roku 1974 i 1975, gdy na zaproszenie LNF we Frascati i CNR (Centro Nazionale delle Ricerche) autor artykułu, jako visiting profesor, wziął udział w badaniach mechanizmu anomalnie wysokiej absorpcji atomowego wodoru w palladzie. Badania spektroskopowe własności układu Pd/H w dalekim próżniowym nadfiolecie miały rozstrzygnąć o mechanizmie tego anomalnego pochłaniania. Niestety, w trakcie badań 1,1 GeV synchrotron uległ nieodwracalnemu uszkodzeniu i został zdemontowany. Cząstkowe rezultaty badań przerwanych awarią synchrotronu zostały zebrane i opublikowane wspólnie z członkami grupy Solidi Roma w roku 1977 [24,28,29]. W roku 1975 jeszcze przed likwidacją 1,1 GeV synchrotronu elektronowego we Frascati, grupa Solidi Roma rozpoczęła, intensywne prace nad wykorzystaniem promieniowania synchrotronowego z 1,5 GeV elektronowego pierścienia akumulującego ADONE, usytuowanego w Narodowym Laboratorium we Frascati (LNF). Przystąpiono wówczas do budowy laboratorium synchrotronowego oraz do projektowania i konstrukcji kilku nowych linii pomiarowych wykorzystujących ADONE jako źródło światła. Działania te koordynował prof. F. Bassani w ramach powstałego wówczas programu użytkowania promieniowania synchrotronowego PULS (Programma per l Utilizazione della Luce di Sincrotrone). W realizację programu włączyła się również poszerzona grupa Solidi Roma. Do współpracy programowej zaproszono także współpracowników z PSOP. Dyrekcja Instytutu Fizyki i administracja centralna UJ intensywnie wspierała wszelkie zabiegi umożliwiające rozwój współpracy PSOP ZFO z grupą Solidi Roma. Rysunek 11. Optyczne linie pomiarowe przy 1,1 GeV synchrotronie: monochromator Mc Pherson na zakres ev (po lewej) i monochromator Hilger & Watts na zakres ev. Prof. E.Burattini ustawia monochromator Mc Phersona. Starania te, opisane szczegółowiej w Kalendarium aktywności Instytutu Fizyki I władz Uniwersytetu Jagiellońskiego w staraniach o dostęp i o wykorzystywanie źródeł promieniowania synchrotronowego w pracach badawczych 15, doprowadziły do zawarcia w roku 1979 umowy o współpracy bezpośredniej normującej realną, wieloletnią, obustronną współpracę pomiędzy Instytutami Fizyki Uniwersytetu Jagiellońskiego i Uniwersytetu Rzymskiego I La Sapienza. Szczególne zasługi w tych staraniach mieli prof. F. Bassani, kierujący grupą Solidi Roma i równocześnie dyrektor Programu PULS oraz profesorowie G. Chiarotti i A. Balzarotti. F. Bassani w czasie wizyty w Instytucie Fizyki UJ w grudniu 1975 roku, na spotkaniu z Rektorem UJ prof. M. Karasiem zaproponował oficjalną współpracę PSOP ZFO z programem PULS we Frascati. Chęć podjęcia współpracy została oficjalnie potwierdzona przez Rektora UJ kilka dni po wyjeździe prof. F. Bassaniego. stosownym listem intencyjnym do prezydenta INFN. Rysunek 10. Pierścień 1.1GeV synchrotronu elektronowego we Frascati. 67 Rysunek 12. Kopuła budynku pierścienia akumulacyjnego ADONE w Narodowym Laboratorium we Frascati. W oparciu o te uzgodnienia, z początkiem roku 1976 profesorowie F. Bassanii i G. Chiarotti wystąpili równocześnie, przez CNR do Polskiej Akademii Nauk i przez Ministerstwo Szkolnictwa Wyższego Republiki Włoskiej do Polskiego Ministerstwa Szkolnictwa Wyższego i Nauki, o zawarcie porozumień o współpracy Instytutu Fizyki UJ z programem PULS w zakresie badań naukowych z użyciem promieniowania do Polskiej

78 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) Akademii Nauk i przez Ministerstwo Szkolnictwa Wyższego Republiki Włoskiej do Polskiego Ministerstwa Szkolnictwa Wyższego i Nauki, o zawarcie porozumień o współpracy Instytutu Fizyki UJ z programem PULS w zakresie badań naukowych z użyciem promieniowania synchrotronowego. Rysunek. 13. Pierścień akumulujący ADONE. Podstawą porozumień o współpracy był program badań przygotowany w PSOP ZFO w roku Przy dużej przychylności władz rektorskich obydwu uniwersytetów, a w szczególności Prorektora UJ Prof. Alojzego Gołębiewskiego, przez dwa lata poprzedzające podpisanie umowy o współpracy bezpośredniej pomiędzy Uniwersytetem Rzymskim La Sapienza i Uniwersytetem Jagiellońskim trwała regularna wymiana współpracowników polskich i włoskich. Wymiana ta zapoczątkowała blisko trzydziestoletnią ścisłą współpracę IF UJ w programach zastosowania promieniowania synchrotronowego w fizycznych i chemicznych badaniach naukowych. Rysunek 14. Prof. M. Piacentini (od prawej) A. Balzarotti w gabinecie autora artykułu. W październiku 1979 r. została podpisana w Krakowie przez Rektorów Mieczysława Hessa i Antonio Ruberti ego formalna umowa o współpracy bezpośredniej pomiędzy uniwersytetami, która przewidywała wspólne badania Instytutów Fizyki obydwu uczelni dotyczące fizyki ciała stałego, w zakresie użytkowania promieniowania synchrotronowego w ramach programu PULS. Odpowiedzialnymi za poprawną realizację dołączonego 68 w aneksie programu badań zostali Prof. F. Bassani oraz autor artykułu. Umowa ta, zawarta w celu realizacji bardzo specjalistycznie potraktowanych zadań badawczych w fizyce ciała stałego, została w latach następnych rozszerzona na współpracę bezpośrednią obydwu uniwersytetów w kilku innych dziedzinach naukowych. Po zawarciu umowy o współpracy bezpośredniej pomiędzy Uniwersytetami Jagiellońskim i Rzymskim w roku 1979, otworzyły się przed PSOP zupełnie nowe możliwości eksperymentalne. W ramach programu PULS - ADONE była na ukończeniu budowa czterech linii eksperymentalnych w tym dwu linii absorpcyjnej spektroskopii rentgenowskiej (XAS) tzn. linii na zakres energii 2 6 kev zwana linią PULS i linii rentgenowskiej PWA (Progetto Wiggler Adone) na twardsze promieniowanie rentgenowskie w zakresie energii 4,5 do 25 kev, linii spektroskopii optycznej w próżniowym nadfiolecie od 6 do 30 ev oraz linii spektroskopii fotoelektronowej (PES). Jako pierwsza, została uruchomiona w roku 1979 linia PULS a następnie linia PWA. Obydwie linie miały służyć do badań lokalnej struktury kryształów metodą EXAFS (Extended X-ray Absorption Fine Structure) i do analizy struktury przykrawędziowej krawędzi rentgenowskich XANES (X-ray Absorption Near Edge Structure), umożliwiającej badanie struktury elektronowej pasma przewodnictwa ciał stałych. Również na linii pomiarowej do badań optycznych w próżniowym nadfiolecie trwały ostatnie prace nad jej uruchomieniem. W tej tak bardzo korzystnej sytuacji, została podjęta decyzja o wykorzystaniu do badań materiałów półprzewodnikowych najpierw dwu wyżej wymienionych linii rentgenowskich a następnie linii optycznej na zakres próżniowego nadfioletu. Zgłoszony przez nas projekt dotyczący analizy struktury krystalicznej w półprzewodnikowych związkach potrójnych Cd 1-x Mn x Te dla różnej zawartości Mn z zastosowaniem metody EXAFS został zaakceptowany i wszedł do realizacji w roku Podjęty program badawczy był nowy i bardzo atrakcyjny naukowo również ze względu na oczekiwaną możliwość łączenia w związkach CdMnTe własności materiałów półprzewodnikowych i magnetycznych. Stwarzało to zapowiedź bardzo obiecujących aplikacji tego typu związków, nazywanych półprzewodnikami półmagnetycznymi lub bardziej poprawnie półprzewodnikami z rozcieńczonym magnetyzmem. Materiały te były badane dotychczas w PSOP metodą fundamentalnego odbicia w zakresie energii promieniowania widzialnego i bliskiego nadfioletu. Instytut Fizyki PAN w Warszawie wytwarzał wysokiej jakości monokryształy tych związków oraz prowadził bardzo szeroki front badań własności strukturalnych, elektrycznych i magnetycznych. Nasza propozycja przeprowadzenia komplementarnych badań opisania lokalnej struktury krystalicznej przy użyciu analizy EXAFS, dostępnej tylko z zastosowaniem promieniowania synchrotronowego oraz własności optycznych w szerokim zakresie energii światła służących poznaniu struktury elektronowej, została przyjęta z zadowoleniem zarówno w Instytucie Fizyki PAN jak i w programie PULS. Eksperymentalna analiza EXAFS wykonana przez grupę włosko-polską 16 na

79 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) próbkach Cd 1-x Mn x Te, została zaprezentowana w trakcie International Conference on EXAFS and Near Edge Structure we Frascati we wrześniu 1982, a następnie w październiku tego roku, jako komunikat na Zjeździe Włoskiego Towarzystwa Fizycznego w Perugii [64]. głównie informacji o splocie gęstości stanów pasm walencyjnego i przewodnictwa (funkcja łącznej gęstości stanów). Natomiast spektroskopia emisji fotoelektronowej i analiza XANES dostarczają informacji odpowiednio o gęstości stanów pasma walencyjnego i pasma przewodnictwa. Mając możliwości badania fundamentalnego odbicia światła i równocześnie szeroki dostęp do analizy XANES można było znacznie wzbogacić wiedzę o strukturze elektronowej badanych półprzewodników. Rysunek 15. Autor artykułu (tyłem) i dr A. Savoya przy optycznej linni pomiarowej PULS w ADONE (1980) Pewnej dozy adrenaliny dostarczyła świadomość, że na konferencji we Frascati amerykanie J.C. Mikkelsen i J.B. Boyce zaprezentowali bardzo podobne wyniki doświadczalne dla potrójnych związków półprzewodnikowych In 1-x Ga x Sb. W obydwu przypadkach brak było odpowiedniej interpretacji odkrytych, ale niezupełnie zrozumiałych cech badanych materiałów. Aby możliwie szybko znaleźć właściwe wyjaśnienie przeprowadzonego eksperymentu zespół polsko-włoski został wzmocniony przez M. Podgórnego i M. Czyżyka, kończących właśnie staże teoretyczne w Dortmundzie. Ich pomysłowość i przygotowanie teoretyczne spowodowały przełom w interpretacji wyników doświadczalnych. Grupa amerykańska opublikowała wyniki badań w the Physical Review w roku 1983, jednakże z interpretacją budzącą poważne wątpliwości 17. Nasze wyniki doświadczalne opublikowaliśmy w tym samym czasopiśmie, kilka miesięcy później, z poprawnym modelowym opisem lokalnej struktury krystalicznej sfalerytu [77, 78, 100]. Wprowadzony przez nas model, później nazwany w literaturze modelem sztywnych kationów, wszedł na trwałe do analizy struktury lokalnej związków potrójnych o strukturze sfalerytu. Wspólnie z grupą włoską przeprowadziliśmy badania jeszcze dla kilku innych związków potrójnych stosując z powodzeniem ten model w interpretacji wyników [64,70,77-80,96-102, ]. Wyniki te zostały zauważone nie tylko w światowej literaturze specjalistycznej. Polscy członkowie zespołu zostali wyróżnieni Zespołową Nagrodą Ministra II stopnia (1986) 18 a ponadto autor artykułu otrzymał w roku 1989 Nagrodę Sekretarza Naukowego PAN 19. Uruchomienie linii rentgenowskiej spektroskopii absorpcyjnej PWA na zakres energii 4 25 kev znacznie poszerzyło zakres badań struktury lokalnej w związkach półprzewodnikowych. Analiza XANES i spektroskopia emisji fotoelektronowej (PES) mogą być metodami komplementarnymi do analizy fundamentalnego odbicia ciał stałych. Fundamentalne odbicie światła dostarcza 69 Rysunek 16. Magnes Wigglera na rentgenowskiej linii PWA w ADONE W roku 1983 PSOP uzyskała dostęp do synchrotronowej optycznej linii pomiarowej w zakresie próżniowego nadfioletu (6 25 ev). Na tej linii zostały przeprowadzone badania przejść rdzeniowych ze stanów d w fundamentalnym odbiciu monokrystalicznych związków ZnTe, CdTe i HgTe, opublikowane w roku 1986 [108,110]. Badania te zapoczątkowały wieloletnią owocną polsko-włoską współpracę w zakresie spektroskopii optycznej półprzewodników, w której widmo fundamentalnego odbicia półprzewodników i metali było mierzone w Krakowie w zakresie 1,5 6 ev, a w zakresie od 6 30 ev na linii optycznej z użyciem promieniowania synchrotronowego z pierścienia kumulującego ADONE we Frascati [122, 124, 170, 175, 179, 182, 185, 187, 188, 190, 196, 199, 203, 205, 206, 221, 241]. Teoretyczną interpretację wyników doświadczalnych opracowywali koledzy z grupy teoretycznej PSOP. Współpraca pomiędzy PSOP i programami PULS oraz PWA trwały nieprzerwanie aż do roku 1994, gdy zakończył pracę pierścień kumulujący ADONE. Zebrana, w ostatnich miesiącach przed zakończeniem pracy ADONE, bardzo duża liczba wyników doświadczalnych dotyczących widm współczynnika odbicia światła w zakresie energii od 6 25 ev oraz krawędzi rentgenowskich (analiza XANES) dla szeregu monokryształów związków potrójnych, siarczków i selenków cynku z wszystkimi metalami przejściowymi, przygotowanych i dostarczonych głównie przez W. Giriata, były opracowywane przez nas jeszcze przez kilka lat po zamknięciu i demontażu ADONE. Po zakończeniu pracy ADONE współpraca ZFO (Zakład Fizyki Ogólnej) z wyżej wymienionymi uniwersytetami włoskimi weszła w nową fazę. Uprzednio zawarte umowy o współpracy bezpośredniej zostały wykorzystane do wspólnych badań, w zakresie

80 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) modulacyjnej analizy fotoakustycznej [220, 242] i emisji fotoelektronowej dla binarnych i potrójnych związków półprzewodnikowych z żelazem [202, 207, 216]. Badania emisji fotoelektronowej zostały wykonane we współpracy trójstronnej z Winsconsin Synchrotron Radiation Centre (USA). W tym okresie były również kontynuowane badania rentgenowskie metodą XANES korzystając z pierścienia kumulującego BESSY I w Berlinie [208, 222] i nowo powstałego pierścienia kumulującego ELETTRA w Trieście. Bilansem doskonale układającej się przez wiele lat współpracy PSOP z grupą Solidi Roma oraz z programami PULS i PWA były znaczące wyniki badawcze w zakresie opisanej powyżej rentgenowskiej analizy EXAFS i XANES, a także liczne rezultaty eksperymentalne w zakresie spektroskopii optycznej od bliskiej podczerwieni do zakresu dalekiego próżniowego nadfioletu. Wyniki te poparte naszymi zaawansowanymi obliczeniami teoretycznymi dostarczyły ważnych informacji o strukturze elektronowej pasma walencyjnego i przewodnictwa wielu badanych podwójnych i potrójnych związków półprzewodnikowych oraz związków potrójnych z metalami przejściowymi. Bezpośrednim rezultatem współpracy było ponad 80 publikacji w czasopismach o cyrkulacji międzynarodowej i czynny udział w wielu konferencjach międzynarodowych. Od roku 1995 w hali po zdemontowanym pierścieniu kumulującym ADONE powstawał w LNF nowy zderzacz (colider) elektronowo-pozytronowy DAΦNE o energii elektronów i pozytronów 0,7 GeV i unikalnie silnym prądzie elektronów i pozytronów (do ok. 2 A) poruszających się w pierścieniu przeciwbieżnie. Wyprowadzane z tego pierścienia promieniowanie synchrotronowe ma kilkakrotnie wyższe natężenie w porównaniu z innymi pierścieniami kumulującymi. Charakterystyka spektralna promieniowania synchrotronowego z DAΦNE, umożliwiła budowę linii pomiarowej do badań absorpcyjnej i emisyjnej spektroskopii rentgenowskiej w zakresie energii od 1,5-4 kev oraz linię spektroskopii optycznej w zakresie dalekiej podczerwieni począwszy od energii kilkudziesięciu cm -1 (FIR). W tym obszarze widmowym są obserwowane wzbudzenia fononowe charakterystyczne dla krystalicznej struktury lokalnej ciał stałych. Z tego względu wyniki analizy wzbudzeń fononowych mogły być konfrontowane z wynikami badań struktury lokalnej kryształów otrzymanymi przy użyciu analizy EXAFS. Prowadzona przez PSOP we współpracy z dr V Robouchem z LNF we Frascati pogłębiona analiza wyników EXAFS wykazała preferencje obsadzeń jonów w potrójnych i poczwórnych roztworach związków półprzewodnikowych [225, 238, 246, 250, 261, 268, 269]. W celu potwierdzenia komplementarności badań struktury lokalnej kryształów przy użyciu analizy EXAFS z badaniami częstości wzbudzeń fononowych kryształów w obszarze dalekiej podczerwieni, PSOP nawiązał współpracę z grupą prof. Eugeniusza Szeregija z Instytutu Fizyki Wyższej Szkoły Pedagogicznej w Rzeszowie (obecnie Uniwersytet Rzeszowski). Nawiązana współpraca umożliwiła rozszerzenie badań prowadzonych przez grupę prof. 70 E. Szeregija przy użyciu konwencjonalnych źródeł światła o badania przeprowadzone we Frascati z użyciem promieniowania synchrotronowego z DAΦNE. Wykorzystanie linii pomiarowej FIR z DAΦNE było możliwe dzięki posiadanym przez PSOP ważnym umowom o współpracy bezpośredniej z Uniwersytetami Rzymskimi La Sapienza i Tor Vergata oraz posiadanemu przez LNF porozumieniu z Unią Europejską o współpracy naukowej. Uzyskane pełne wyniki eksperymentalne częstości i natężeń wzbudzeń fononowych dały możliwość przeprowadzenia badań preferencji obsadzeń jonów w potrójnych i poczwórnych roztworów stałych związków półprzewodnikowych grupy II VI. Oczekiwane preferencje obsadzeń jonów zostały potwierdzone w odpowiednich natężeniach drgań fononowych badanych związków półprzewodnikowych [260, 265, 266]. Warto na końcu tego rozdziału ocenić efektywność współpracy polsko-włoskiej pomiędzy Instytutem Fizyki UJ i Instytutami Fizyki Uniwersytetów w Rzymie i w Trento oraz grupą Solidi Roma i programem PULS na tle stanu badań naukowych prowadzonych z użyciem promieniowania synchrotronowego przez Polaków afiliowanych w Polsce. Ta ocena została oparta na spisie publikacji i dysertacji wykonanych przy użyciu promieniowania synchrotronowego przez polskich autorów afiliowanych w polskich instytucjach naukowych, zamieszczonym w internecie przez Polskie Towarzystwo Promieniowania Synchrotronowego (PTPS) 20. Spis ten informuje, że najwcześniejsze publikacje z udziałem Polaków pochodziły z roku Dotyczyły one przygotowywania w Narodowym Instytucie Fizyki Jądrowej (INFN) we Frascati cienkich warstw Pt nasycanych wodorem, przeznaczonych do badań optycznych w próżniowym nadfiolecie z użyciem promieniowania synchrotronowego z 1,1 GeV synchrotronu [24, 28, 29]. Publikacje te były rezultatem, omawianej powyżej, współpracy Instytutów Fizyki Uniwersytetu Jagiellońskiego i Uniwersytetu Rzymskiego I La Sapienza, zapoczątkowanej przez te instytucje w pierwszej połowie lat siedemdziesiątych ubiegłego wieku. Według spisu PTPS w dziesięcioleciu ukazały się 34 publikacje z udziałem polskich autorów afiliowanych w Polsce. Autorzy reprezentowali: Instytuty Fizyki Uniwersytetu Warszawskiego, Politechniki Warszawskiej i Uniwersytetu Jagiellońskiego oraz Instytut Fizyki PAN w Warszawie i Instytut Fizyki Jądrowej w Krakowie. Wśród tych publikacji aż 21 artykułów było wynikiem współpracy IF UJ z Uniwersytetem Rzymskim I i grupą Solidi Roma. Stanowiło to 68% całej aktywności Polaków w dziesięcioleciu W następnym pięcioleciu ( ) aktywność naukowa polskich użytkowników promieniowania synchrotronowego znacznie wzrosła. Podjęli współpracę kolejni badacze i instytuty naukowe. W tym okresie opublikowano 85 artykułów, z czego blisko 25% (22 publikacje) było wynikiem współpracy polsko-włoskiej pomiędzy IF Uniwersytetu Jagiellońskiego a IF Uniwersytetu Rzymskiego i IF Uniwersytetu w Trento oraz programem PULS. Przytoczone zestawienie aktywności naukowej PSOP IF UJ w porównaniu z piętnastoletnim

81 Synchrotron Radiation in Natural Science Vol. 14, No. 1-2 (2015) ogólnopolskim użytkowaniem promieniowania synchrotronowego w badaniach naukowych, uzmysławia celowość organizowanej konsekwentnie przez Instytut Fizyki Uniwersytetu Jagiellońskiego, od pierwszej połowy lat siedemdziesiątych ubiegłego stulecia, ścisłej współpracy polsko-włoskiej ukierunkowanej na stosowanie promieniowania synchrotronowego w fizyce ciała stałego. Współpraca PSOP z Polskim Towarzystwem Promieniowania Synchrotronowego Wraz z coraz bardziej intensywnym rozwojem badań z użyciem promieniowania synchrotronowego w latach osiemdziesiątych ubiegłego stulecia, fizycy i chemicy oraz współpracujący z nimi lekarze i biologowie zaczęli wyrażać potrzebę integracji polskiego środowiska naukowego, pracującego przy różnych źródłach promieniowania synchrotronowego. Wychodząc naprzeciw temu zapotrzebowaniu PSOP ZFO prowadząca intensywne badania z użyciem promieniowania synchrotronowego w zakresie absorpcyjnej spektroskopii rentgenowskiej i spektroskopii optycznej półprzewodników, podjęła się wspólnie z Instytutem Fizyki PAN w Warszawie organizacji pierwszego Sympozjum Użytkowników Promieniowania Synchrotronowego. W lutym 1991 roku z inicjatywy i staraniem profesora Juliana Auleytnera oraz autora artykułu, odbyło się w Uniwersytecie Jagiellońskim, w pałacyku Szyszko-Bohusza I Krajowe Sympozjum Użytkowników Promieniowania Synchrotronowego. Na Sympozjum wygłoszono 25 piętnastominutowych komunikatów z badań prowadzonych przez polskich badaczy przy użyciu promieniowania synchrotronowego. Uczestnicy Sympozjum zadeklarowali chęć utworzenia Polskiego Towarzystwa Promieniowania Synchrotronowego (PTPS). Wśród 28 członków założycieli było dwunastu z Instytutu Fizyki i Chemii UJ, w tym osiem osób z PSOP ZFO. Pozostali reprezentowali Instytut Fizyki PAN w Warszawie, Uniwersytet Warszawski i kilka innych ośrodków. W maju 1991 r. Towarzystwo zostało zarejestrowane z siedzibą w Instytucie Fizyki UJ i rozpoczęło działalność integracyjną i edukacyjną powstającego środowiska naukowego poprzez organizację międzynarodowych szkół i sympozjów. PSOP ZFO włączyło się bardzo aktywnie do działalności w PTPS organizując Drugie Krajowe Sympozjum Użytkowników Promieniowania Synchrotronowego w Mogilanach (1993) i Czwarte Krajowe Sympozjum w Domu Polonijnym Uniwersytetu Jagiellońskiego w Przegorzałach (1997) oraz uczestniczyło czynnie we wszystkich inicjatywach PTPS. Szczegóły tej działalności zostały przedstawione w Kalendarium starań Instytutu Fizyki (notka 14) oraz Kalendarium starań Polskiego Towarzystwa Promieniowania Synchrotronowego o dostęp do europejskich źródeł promieniowania synchrotronowego 21. Zapraszanie wielu wybitnych specjalistów z ośrodków synchrotronowych na organizowane przez PTPS i odbywające się regularnie międzynarodowe sympozja i szkoły ułatwiało nawiązywanie kontaktów i tworzenie owocnej współpracy przez polskich uczestników 71 międzynarodowych szkół i sympozjów oraz sympozjów krajowych. Rysunek 17. Uczestnicy 1-szej Międzynarodowej Szkoły i Sympozjum Promieniowania Synchrotronowegow Naukach Przyrodniczych (1992). W pierwszym rzędzie stoją profesorowie B. Orłowski, I. Sosnowska, autor artykułu, J. Auleitner, G. Margaritondo, M. Antonetti oraz K. Jabłońska. W dalszych rzędach m. in. W. Wierzchowski, J. Haertwig, E. Sobczak, W. Kwiatek, R. Haensel, J. Nordgren, C. Malgrange, A. Kvick Uwagi końcowe Po przejściu autora artykułu na emeryturę w roku 2002, Zakład Fizyki Ogólnej i Pracownie należące do Zakładu zostały rozwiązane. Personel Zakładu został włączony do Zakładu Fizyki Doświadczalnej, z którego ZFO wyodrębnił się w roku W trzydziestodwuletniej działalności naukowej ZFO były prowadzone intensywne badania naukowe w niełatwej eksperymentalnie spektroskopii interferencyjnej, spektroskopii optycznej półprzewodników, absorpcyjnej spektroskopii rentgenowskiej, spektroskopii fotoemisji elektronowej, spektroskopii fononowej i spektroskopii molekularnej. Uzyskane wyniki badań były zauważane przez specjalistów. Opublikowano około 270 artykułów i komunikatów w większości w czasopismach o cyrkulacji międzynarodowej. W ZFO doktoryzowało się 15 asystentów i doktorantów 22 a 4 osoby habilitowały się 23. Szereg prac doktorskich zostało nagrodzonych Nagrodami Indywidualnymi III stopnia Ministra Nauki, Szkolnictwa Wyższego i Techniki. W chwili rozwiązania ZFO liczył 9 pracowników: dwu doktorów habilitowanych J. Koniora i M. Stankiewicza, czterech starszych wykładowców: R. Kloch, B. Pukowską, J. Szczeklika i M. Zimnal-Starnawską, dwu samodzielnych fizyków: E. Czarnecką-Such i J. Olejniczaka oraz starszego elektronika R. Samsona. Doktorzy habilitowani J. Konior i M. Stankiewicz otrzymali tytuły profesora w roku Prof. J. Konior należy obecnie do Zakładu Nanostruktur i Nanotechnologii, a prof. M. Stankiewicz jest dyrektorem Narodowego Centrum Promieniowania Synchrotronowego Solaris, w którym od wiosny bieżącego roku trwa rozruch pierwszego polskiego synchrotronu SOLARIS. Będzie on służyć jako źródło promieniowania synchrotronowego przeznaczone do badań w naukach przyrodniczych. Zbudowane źródło promieniowania synchrotronowego jest wielką szansą