Degradation of BPSCCO superconductors during processing

Evaporation losses of Bi, Sr, Cu and Pb during processing of Bi-Pb-Sr-Ca-Cu -oxide (BPSCCO) superconductors were observed, which affected the supercond ucting properties. Incongruent loss of Bi, Sr, Cu and Pb was reduced by cov ering the pellets by excess BPSCCO powder during sintering and formation of the 2223 phase was observed to be enhanced. Formation of low temperature e utectic by silver addition was observed to accelerate the rate of evaporati on. Lower temperature processing was required for fabrication of high quali ty Ag sheathed BPSCCO tapes. (C) 1999 Kluwer Academic Publishers.