Anodic and dissolution characteristics of Ba sub 2 YCu sub 3 0 sub 7 in aqueous electrolytes. Electrolytes.

We have examined the electrochemical reactions taking place at Ba sub 2 YCu sub 3 0 sub 7 and Cu0 in several aqueous media under anodic and open circuit conditions. Understanding of reactions of these materials in water containing environments may be important in their fabrication into devices and practical applications. Ba sub 2 YCu sub 3 0 sub 7 is dissolved by aqueous acids at mass transport limited rates up to 0.1M in H sup + concentration in 1M NaCl with no selectivity for metal ions, i.e. they are found in stoichiometric ratios. This conclusion was determined by analysis following controlled exposure of rotating disk electrodes of the high temperature superconductor. When these disks are anodized at constant current in NaCl or NaClO sub 4 media, essentially only Ba dissolves. In pH 6. 9 phosphate buffer or 1M NaOH lesser fractions are found in solution. Anodization in saturated CaCl sub 2 produces chlorine and non-selective dissolution of the substrate simultaneously. Chemistry for these various situations is proposed.