Processing and Superconducting Properties of GdBa₂Cu₃O_7-δ Ceramics

Abstract

The influences of the processing of the high- T c superconductor GdBa 2 Cu 3 O 7-δ prepared under various sintering conditions on the superconducting properties were investigated. The volume fraction of the superconducting phase at 77 K increased monotonically with an increase in the sintering temperature. The critical current density measured by the resistive method showed a maximum value for the sample sintered at 930°C, while the estimated value from the magnetization loop increased with an increase in the sintering temperature, though the critical temperatures of all the samples annealed in oxygen atmosphere were about 90 K. This difference was discussed in terms of the microstructure of the superconducting ceramic.