TG-DTA Study on the High T_c Superconductor YBa₂Cu₃O_x Ceramics

Abstract

Thermal analysis of superconducting YBa₂Cu₃O_x ceramics was studied by TG-DTA between 25° and 900°C. The weight loss due to release of structural oxygen was 1.5%, 1.3% and 2.0% in air, oxygen and nitrogen, respectively. The YBa₂Cu₃O_x ceramics absorbed oxygen rapidly around 330°C. Change of oxygen content of this compound was reversible under the cycle of heat treatment in oxygen containing atmospheres. The phase transition from orthorhombic to tetragonal structure occurred at 570°C in nitrogen, 620°C in air and 680°C in oxygen atmospheres.