SUPERCONDUCTING PROPERTIES OF MGO-WHISKER REINFORCED BPSCCO COMPOSITE

Based on a recently introduced solid-state processing method, a new cl ass of high-temperature BPSCCO (2223) ceramic matrix composites reinfo rced with MgO whiskers has been developed. The (MgO)(w)/BPSCCO composi tes are shown to possess attractive superconducting properties with si gnificantly improved mechanical properties. It is recognized that the superconducting properties of the (MgO)(w)/BPSCCO HTS composites are r elated to proper material microstructures achievable by optimizing the processing variables involved, such as repeated hot pressing and anne aling, hot-pressing temperature and pressure level, and the length of annealing. In this paper, relationships among superconducting properti es and composite processing variables are established. Also, effects o f the BPSCCO (2223) phase purity and the MgO whisker reinforcement on superconducting properties of the (MgO)(w)/BPSCCO composites are discu ssed. The important issue of the field dependence of superconducting p roperties of both the monolithic and the composite HTS materials is ad dressed.