Search academic texts

Information × Registration Number 0304U004186, 0103U004203 , R & D reports Title Influence of relax processes on functional properties of multicomponent crystal systems popup.stage_title ДОСЛІДЖЕННЯ СТРУКТУРИ ФАЗОВИХ ПРОШАРКІВ ТА ВНУТРІШНІХ НАПРУЖЕНЬ, ЩО ВИНИКАЮТЬ ПРИ ФОРМУВАННІ ДИФУЗІЙНОЇ ЗОНИ ТА ОПРОМІНЮВАННІ В ПРИПОВЕРХНЕВИХ ШАРАХ КРИСТАЛІВ Head Matsokin V.P., Registration Date 26-03-2004 Organization Kharkov National University named after V.N.Karazin popup.description2 The objects under investigation were multiphase systems Cu-Ni-5at%Sn and Cu-Ni-5at%In with limited solubility of Sn and In in Cu and Ni, and single crystals of CaF2, KCl and NaCl. The multiphase systems were composed from homogeneous alloys Cu-5at%Sn / Ni-5at%Sn and Cu-5at%In /Ni-5at%In. The aims of the study were: to determine the peculiarities of interdiffusion in the multicomponent crystal structures with a small additive of the third component; to discover the internal stress distribution at point phase formation and possible mechanisms of the stress relaxation; to register and to determine the size of the surface tracks in CaF2; to compare the tracks size on the surface of CaF2 to those on the surface of LiF; to determine the correlation between two parallel planar imperfections and the parameters of dispersion law of the system, at which such a system can be considered as a quantum waveguide with the modes capable of spreading across the defects surface. Following methods of investigation were used: metallography, optical and scanning electron microscopy, X-Ray analysis, and numerical calculations. Interdiffusion in diffusion vapours, composed of Cu -5at% Sn(In) and Ni-5at% Sn(In) alloys was studied. It was shown that the redistribution of the components with the formation of concentration peaks at Ni-side of forming diffusion zones takes place at the zeroth initial value of the concentration gradient. The ascending diffusion of Sn and In discovered was conditioned by the interaction of kinetic and thermodynamic properties of three-component systems. The distribution of stresses formed in the near-surface layers of crystal at point phase formation and the mechanisms of their relaxation were analyzed. The tracks formed in the near-surface layers of single crystals of CaF2 at irradiation by heavy multicharged ions were observed and studied for the first time. It was shown that the energy scattered by the ion should exceed the evaporation (?vaporization?)energy for the formation of the tracks on the surface of refractory crystals. The system the dispersion law of which has two branches was considered. Correlation between two parallel planar imperfections and the parameters of dispersion law of the system, at which such a system can be considered as a quantum waveguide with the modes capable of spreading across the defects surface was determined. The results of the study may be used for the development of theory, technology, and exploitation of modern multicomponent heat-resistant materials, also for the solution of the tasks concerned with the relaxation of energy in near-surface layers of crystals at irradiation by heavy multicharged ions and elastic vibrations. Product Description popup.authors popup.nrat_date 2020-04-02 Close