Vapor Pressure of Barium and Copper Components in YBa ₂ Cu ₃ O 7− x Superconductor Ceramics

Purified air is passed over a specimen of YBa 2 Cu 3 O 7– x at 890°C; the vaporized substances are condensed in a pure alumina tube, then subjected to inductively controlled plasma analysis. Vapor pressure values of 2.5 × 10 −5 Pa for BaO( g ), 1.2 × 10 −4 Pa for Cu( g ), and 2.2 × 10 −5 Pa for CuO( g ) are obtained under 2.1 × 10 4 Pa (0.21 bar) of oxygen pressure. No Y vapor is detected at this temperature.