Joining of Hot-Pressed Bi-Pb-Sr-Ca-Cu-O Superconductor

Abstract

Hot-pressed Bi_0.85Pb_0.15Sr_0.8CaCu_1.4O _y superconductors were joined without an interfacial layer at 780°C at a pressure of 25 kg/cm² in air for 30 min. Then the joined sample was annealed at 830°C in air for 40 h. No appreciable void was observed at the joining interface. The resistivity in the normal conducting state and the T _c of the joined sample were almost equal to those of the base sample. However, the J _c of the joined sample and the base sample were 241 A/cm² and 375 A/cm² at 77 K in zero magnetic field, respectively. The decrease in J _c seems to be due to a weak link at the joining interface.