Change on the Surface of Superconducting Oxide Ba₂EuCu₃O_7-x under Various Humid Atmospheres

Abstract

The stability of the superconducting phase of Ba₂EuCu₃O_7-x was studied under various humid atmospheres at 25°C by XRD, SEM and EPMA. The superconducting oxide completely disintegrated within 1400h above 80% RH, while it remained stable for a long time below 60% RH. The superconducting oxide would disintegrate by forming BaCO₃ via Ba(OH)₂ above 80% RH. It formed only a small amount of precipitate which was considered to be BaCU(OH)₄ below 60% RH.