Processing techniques for the 93K superconductor Ba sub 2 YCu sub 3 O sub 7.

Superconductivity above the temperature of liquid nitrogen in copper oxide based systems has led to optimism that superconductors may at last find wide spread applications. The critical temperature (T sub c), however, is just one of the required parameters. The materials must be made into useable forms such as wire, thick films, thin films, and bulk ceramics. In addition, the critical current (J sub c) in these various forms is a crucial test of their utility. This article reviews the processing techniques used to fabricate potentially useful forms and assesses remaining problems. Considerable improvement in J sub c is necessary in bulk materials and thin films need to be made compatible with other thin film technology.