http://dspace.nbuv.gov.ua:80/handle/123456789/132724 2026-04-20T17:17:04Z http://dspace.nbuv.gov.ua:80/handle/123456789/135284 Researches and developments on production of Ni-W alloy based substrates for second generation high-temperature superconductors Finkel, V.A.; Bovda, A.M.; Derevyanko, V.V.; Leonov, S.A.; Sungurov, M.S.; Sukhareva, T.V.; Khoroshikh, V.M.; Shakhov, Yu.N. The possibilities to prepare high quality substrates for second generation high temperature superconductors based on Ni—W alloys in the 0-9.5 at. % W concentration range was studied. Researches and developments were carried out in the following directions: a) Ni—W alloy synthesis; b) preparation of Ni—W alloy tapes by rolling with subsequent heat treatment; c) coating the tape by TiN layer. For the first time, the possibility was established to obtain the {001} <100> cubic texture favour to YBa₂Cu₃O₇₋₈ superconductor subsequent epitaxial growth on the high W paramagnetic Ni—W tape surface by varying the regimes of TiN deposition. 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/135283 Modeling of magnetic and magnetocaloric properties of La₀̣.₇Ba₀.₃MnO₃ manganites by Monte Carlo method Pavlukhina, O.; Buchelnikov, V.; Sokolovskiy, V. In the work the temperature dependence of magnetization, entropy changes, and the Curie temperature of La₀̣.₇Ba₀.₃MnO₃ using Monte Carlo method and Heisenberg model were investigated. We used the magnetic exchange parameters from the first-principles calculations. In the simulation, magnetic Mn³ᐩ and Mn⁴ᐩ ions are described by classical Heisenberg spins, while oxygen, lanthanum and calcium ions are considered as non-magnetic. Mn magnetic ions are distributed on R3c lattice according to the perovskite structure of the manganite. The Curie temperature and magnetocaloric effect values obtained during the theoretical simulations are in a good agreement with the experimental data. 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/135282 Resolving power of scintillation panels based on zinc selenide Litichevskyi, V.; Galkin, S.; Lalaiants, O.; Voronkin, E.; Mahota, S.; Breslavskiy, I. This work presents some characteristics of experimental samples of flexible scintillation panels made on the basis of fine-powders of zinc selenide scintillator. The purpose of the work was to determine the resolving power of dispersed scintillation panels based on ZnSe(Te) and to clarify the field of their application in X-ray technique. In the course of studying the dependences of the resolving power of scintillation panels based on ZnSe(Te) on the powder particles size and thickness of the panels were discovered. The data on the dependences of the light output on the panel thickness and particle size of the scintillator in the samples in the thickness range of 0.1-1 mm are presented. X-ray images of different test objects obtained using scintillation panels based on zinc selenide are shown. Three ranges of the particles dispersion were investigated: the first — 25-40 µm, the second — 40-120 µm, and the third — 120-200 µm. It was revealed that the resolving power was 5, 3 and 2.5 lp/mm for the each range of dispersion. 2012-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/135281 Nonlinear-optical phases in strontium tetraborate-lead tetraborat system Oseledchik, Yu.S.; Prosvirnin, A.L.; Lutsenko, V.Yu. The phase diagram of strontium tetraborate SrB₄O₇ — lead tetraborat PbB₄O₇ system was specified by means of improved DTA technique. Concentration dependence of phases formation, trigonal p or orthorhombic a, by low-temperature crystallization of the glasses (1-x)SrB₄O₇-xPbB₄O₇ (0≤x≤1) was studied. Only the metastable trigonal phase β-Sr₁₋xPbxB₄O₇ for concentration x<0.2 is crystallized. The both high nonlinear phases of strontium-lead tetraborates (deff (β-Sr₀.₈Pb₀.₂B₄O₇) ~~ deff (PbB₄O₇)) are perspective for use as the non-linear-optical crystals components of glass-ceramic materials on the basis of strontium tetraborate-lead tetraborate system. 2012-01-01T00:00:00Z