Superconducting properties of MgO-whisker reinforced BPSCCO composite

Based on a recently introduced solid-state processing method, a new class of high-temperature BPSCCO (2223) ceramic matrix composites reinforced with MgO whiskers has been developed. The (MgO)_w/BPSCCO composites are shown to possess attractive superconducting properties with significantly improved mechanical properties. It is recognized that the superconducting properties of the (MgO)_w/BPSCCO HTS composite are related to proper material microstructures achievable by optimizing the processing variables involved, such as repeated hot pressing and annealing, hot-pressing temperature and pressure level, and the length of annealing. In this paper, relationships among superconducting properties and composite processing variables are established. Also, effects of the BPSCCO (2223) phase purity and the MgO whisker reinforcement on superconducting properties of the (MgO)_w/BPSCCO composites are discussed. The important issue of the field dependence of superconducting properties of both the monolithic and the composite HTS materials is addressed.