ENHANCEMENT OF THE CRITICAL PARAMETERS OF BI-2212 OBTAINED BY SOLID-STATE REACTION AND SINTERING

Bi2Sr3-xCaxCu2Oz (x = 1.0, 1.1, 1.5, 1.8) with a density of 65-70% of theoretical and transition endpoint T-cf = 77 K was prepared by the st andard ceramic technique, sintering in air, and furnace-cooling or que nching. Explosive pressing enhanced the density to 85-90% and T-cf to 80-87 K (at x = 1.0, 1.5). With increasing Ca content, the content of 2212 increases but the superconducting properties degrade. The critica l parameters of the 2212 ceramics were found to be enhanced by thermal treatment at reduced oxygen pressures or by densification of compacts . The critical current density in densified ceramics attained 100-200 A/cm(2).