Nychyporuk O. Synthesis and properties of high-temperature superconducting materials on the basis of rare earth metals in different oxidation states

Dissertation is dedicated to optimization of synthesis methods of high temperature superconductors on the basis of rare earth elements and bismuth, electrophysical properties, oxygen content and conditions of thermal processing, influence of polymer phase on HTSC properties. Homogenity regions for LnBa2Cu3Ox (Ln: Y, Eu, Er), Ln1-xRxBa2Cu3Oy (Ln: Y, Eu, Er) (R : Pr, Tb, Ce) (0 ?x ?0,5), Y1-xR0.5xBa2+0.5xCu3Oy (R : Pr, Tb, Ce) (0,1 ?x ?0,5)were defined , oxygen index changes, crystal lattice parameters and types were investigated in dependence of composition of samples, electrophysical investigations were conducted. Polyner-ceramic composite samples on the basis of YBa2Cu3Oу superconductive ceramic were synthesized. Influence of polymer phase on the properties of HTSC samples was investigated and it was shown that this leads to increasing of stability of such polymer-organic materials to influence of water evaporation. Homogenity regions for LnBa2Cu4O8 (Ln: Y, Eu, Er),Ln1-xRxBa2Cu4O8 (Ln: Y, Eu, Er) (R :Pr, Tb, Ce) (0 ?x ?0,5)were defined , their phase composition was investigated. It was shown that there is a connection between critical temperature and phase composition.