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Information × Registration Number 0219U003553, 0116U000827 , R & D reports Title Evolution of the material properties of polyfunctional purposes under extreme external factors popup.stage_title Head Ruslan Vovk, Доктор фізико-математичних наук Registration Date 23-01-2019 Organization Kharkov National University named after V.N. Karazin popup.description2 Objects of experimental research: MAX-phases of Ti3AlC2 and ceramics of Al2O3-SiC; layered structures - HTSC YBa2Cu3O7-?. The purpose of the work is to study the features of transport of charge and heat. The method of research is the experimental determination of electrical and thermal conductivity, depending on external factors; analysis of the obtained dependencies. The electrical and thermal conductivity of the sample of the MAX-phase Ti3AlC2 has been experimentally investigated in the temperature range 15-300 K. The temperature dependence of the electric resistance is determined by scattering of electrons by phonons and defects. In the region of elastic scattering of electrons, the proportion of phonon heat transfer decreases from ~ 90% at low temperatures to ~ 40% near room temperature. The optimum conditions for electroconcoliation, which provide greater hardness and thermal conductivity, are determined in the research of thermal conductivity in the range of 15 ? 300 K samples of ceramic composites Al2O3-SiC, than in modern materials for incisors. The diffusion coalescence of oxygen clusters as a mechanism for redistribution of oxygen in YBa2Cu3O7-x is proposed. External hydrostatic pressure significantly intensifies the process of diffusion coalescence of oxygen clusters, that is, it causes an increase in their average size. The influence of irradiation by high-energy electrons on the electric resistance of optimally doped oxygen by YBa2Cu3O7-x both in ab-plane and along the axis c is investigated. The irradiation creates in the sample oriented macroscopic regions along the layers, which differ in oxygen deficiency, which leads to jump transverse conductivity with variable jump length. An increase in the radiation dose leads to a decrease in the localization of the charge carriers. As a result of electron irradiation, the residual resistance increases, the phonon spectrum becomes more isotropic, the temperature of the superconducting transition decreases, and the superconducting transition expands. Electronic irradiation does not affect excessive conductivity. Research results can be used to create materials with predefined characteristics. Electrical conductivity, thermal conductivity, electrocasolidated ceramics, HTSC, phonons, electrons, anisotropy, coalescence. Product Description popup.authors І. Любчанський Г. Хаджай Е. Геворкян Л. Холодилова О. Гриб Р. Вовк popup.nrat_date 2020-04-02 Close