Modern materials ****************************************************************************************** * Modern materials ****************************************************************************************** Ultra fine grained and nanocrystalline materials belong to an important group of modern ma unusual properties that are very attractive for different structural and functional applic techniques of preparation of these materials are based on the imposition of very high stra exceptional grain refinement without any significant change of the overall dimensions. Hig pressures are applied during these processes which introduce high densities of lattice def dislocations or vacancies) and result in the formation of special structures. Materials fa these techniques, called severe plastic deformation, exhibit several unique properties inc strength, ductility and fatigue endurance, increased superplastic capabilities as well as behaviour when materials exhibit enhanced functional (electric, magnetic, corrosion, etc.) properties. For several years we have been dealing with structure investigations of various types of n (semiconductor quantum wires dots, metallic nanoparticles, etc.) using x-ray based methods ray diffraction, small-angle x-ray scattering and x-ray absorption spectroscopy. Several y have started a study of the structure of new materials, like antiferromagnetic semiconduct and topological insulators. We perform the experiments in the x ray lab of the Department Matter physics. Moreover, we are frequently using various synchrotron and neutron sources (Grenoble), ANKA (Karlsruhe), ELETTRA (Trieste), APT (Argonne Nat. Lab.), PSI (Villingen), ****************************************************************************************** * Selected outputs ****************************************************************************************** • M. Janeček, J. Stráský, J. Čížek, P. Harcuba, K. Václavová, V.V. Polyakova, I.P. Semenov properties and dislocation structure evolution in Ti6Al7Nb alloy processed by high press Met. Mat. Trans. A 45, 7-15 (2014). • J. Šmilauerová, P. Harcuba, J. Stráský, J. Stráská, M. Janeček, J. Pospíšil, R. Kužel, T Holý, and J. Ilavský: Ordered array of omega particles in beta-Ti matrix studied by smal scattering. Acta Mater. 81, 71-82 (2014). • J. Růžička, O. Caha, V. Holý, H. Steiner, V. Volobuiev, A. Ney, G. Bauer, T. Duchoň, K. I. Khalakhan, V. Matolín, E. F. Schwier, H. Iwasawa, K. Shimada, and G. Springholz: Stru electronic properties of manganese-doped Bi2Te3 epitaxial layers. New J. Phys. 17, 01302 • J. Čížek, M. Janeček, T. Krajňák, J. Stráská, P. Hruška, J. Gubicza, H.S. Kim: Structura characterization of ultrafine-grained interstitial-free steel prepared by severe plastic Acta Materialia 105 (2016), 258-272 • T. Krajňák, P. Minárik, J. Gubicza, K. Máthis, R. Kužel, M. Janeček: Influence of equal pressing routes on texture, microsctructure and mechanical properties of extruded AX41 m Materials Characterization 123 (2017), 282-293 • P. Strunz, J. Šmilauerová, M. Janeček, J. Stráský, P. Harcuba, J. Pospíšil, J. Veselý, P Karge: Evaluation of anisotropic small-angle neutron scattering data from metastable ?-T Mag. 98 (2018), 3086-3108. • G. Springholz, S. Wimmer, H. Groiss, M. Albu, F. Hofer, O. Caha, D. Kriegner, J. Stangl, Holý, Structural disorder of natural BimSen superlattices grown by molecular beam epitax Materials 2, 054202 (2018)