http://hdl.handle.net/123456789/85 2026-05-15T07:54:08Z http://hdl.handle.net/123456789/3487 Title: Mossbauer Study Of Yttrium Iron Garnet Epitaxial Films Magnetic Microstructure Authors: Kotsyubynsky, Volodymyr; Moklyak, V.; Ostafiychuk, B. Abstract: The magnetic microstructure of the yttrium iron garnet epitaxial films surface layer were studied by conversion electronic Mossbauer spectroscopy method. The presence of two magnetically non-equvivalent positions of Fe3+ ions in tetrahedral sites of garnet structure and a paramagnetic phase formed by Fe2+ ions were fixed. Using the model of mixed magnetic and quadrupole interaction by the diagonalization of the nuclear Hamiltonian matrix the information about the spatial orientation of the cation sublattices magnetic moments was obtained and the components of electric field gradient tensor at 57Fe nuclei in different crystal non-equvivalent positions were calculated 2014-01-01T00:00:00Z http://hdl.handle.net/123456789/3486 Title: Temperature Frequency Characteristics Of Charge Transition In The Li0.5fe2.4ti0.1o4 Non-Stoichiometric System Authors: Gasyuk, I.; Ugorchuk, V.; Kaykan, L.; Deputat, B. Abstract: A study of conductivity temperature frequency dependence of Li0.5Fe2.4Ti0.1O4 non-stoichiometric spinel has exhibited frequency dispersion conductivity presence. The time of relaxation (τ) proved to make 2·10-6s within the limits of dispersion. The conductivity size was found to be dependant upon the amount of Fe2+ions in the structure. 2014-01-01T00:00:00Z http://hdl.handle.net/123456789/3485 Title: Quantum-Dimensional Effects In Thermoelectric Characteristics Of Lead Chalcogenides Nanostructures Authors: Freik, D.; Yurchyshyn, I.; Potyak, V. Abstract: On the basis of theoretical model of quantum well (QW) with infinitely high walls it was investigated thermoelectric parameters depending on the thickness of the layer of nanostructures IV-VI (PbS, PbSe, PbTe) in the approximation of changing Fermi energy. There have been shown that the dependences of the Seebeck coefficient, electrical conductivity and thermoelectric power factor on well width for lead chalcogenides nanofilms are in good agreement with the experimental data. So, that proves the correctness of used model. 2014-01-01T00:00:00Z http://hdl.handle.net/123456789/3484 Title: Crystal-Quasichemical Analysis Of Defect Subsystem Of Doped Pbte: Sb Crystals And Pb-Sb-Te Solid Solutions Authors: Freik, D.; Turovska, L. Abstract: Within crystalquasichemical formalism models of point defects of crystals in the Pb-Sb-Te system were specified. Based on proposed crystalquasichemical formulae of antimony doped crystals PbTe:Sb amphoteric dopant effect was explained. Mechanisms of solid solution formation for РbТе-Sb2Те3: replacement of antimony ions lead sites with the formation of cation vacancies (I) or neutral interstitial tellurium atoms (II) were examined. Dominant point defects in doped crystals PbTe:Sb and РbТе-Sb2Те3 solid solutions based on p-PbTe were defined. Dependences of concentration of dominant point defects, current carriers and Hall concentration on content of dopant compound and the initial deviation from stoichiometry in the basic matrix were calculated. 2014-01-01T00:00:00Z