Nonstoichiometry of superconducting Ba2YCu3O7−y at temperatures between 870 and 1180 K

A thermogravimetric technique was employed for the determination of the nonstoichiometry of Ba2YCu3O7-y at temperatures between 870 and 1180 K and the oxygen partial pressure of 0.005 to 1 atm. The oxygen deficiency, y, varied from 0.8 to 1.3, corresponding to the presence of Cu2+ and Cu+ at the temperatures investigated.