Formation of YBa₂Cu₃O_x by peritectic reaction

Abstract

The decomposition process on heating and the crystallization process from a liquid on cooling for high-Tc superconductor YBa₂Cu₃O_x(x - 7) have been studied through thermal analysis, microstructural observation, compositional and X-ray analyses. On heating, YBa₂Cu₃O_x decomposes at 993°C in air to Y₂BaCuO₅ and a liquid due to an incongruent melting. On cooling, YBa₂Cu₃O_x crystallizes around the primary crystal Y₂BaCuO₅ from a liquid as a result of a peritectic reaction. YBa₂Cu₃O_x was also found to grow markedly in the sample cooled slowly to 760°C from 1200°C.