Process of making a superconducting glass-ceramic composition

A process for preparing a superconductive glass-ceramic composition, comprising the steps of:

• (a) providing a homogeneous powder batch, wherein said batch is comprised of from about 35 to about 50 weight percent of barium oxide, from about 6 to about 18 weight percent of boron oxide glass former, from about 25 to about 35 weight percent of cupric oxide, and from about 12 to about 18 weight percent of yttrium oxide, and wherein the concentration of each of such reagents is calculated on the oxide basis in weight percent, by combined weight of the barium, yttrium, copper, and boron components;
• (b) heating said homogeneous powder batch to a temperature of from about 1170 degrees to about 1300 degrees Celsius until the batch becomes molten, wherein said powder batch is maintained under an oxygen-containing atmosphere during said heating;
• (c) reducing the temperature of the molten batch from the temperature of the melt to ambient temperature, thereby producing glass;
• and
• (d) heat-treating said glass by subjecting it to a temperature of from about 750 degrees to about 950 degrees celsius.