Ag-sheathed Bi-Pb-Sr-Ca-Cu-O superconducting wires with high critical current density

Critical current density ( J c ) and its dependence on magnetic field in Ag-sheathed Bi-Pb-Sr-Ca-Cu-O superconducting wire was improved by grain alignment and homogenization of the high- T c phase (110 K). The maximum transport current density at 77.3 K in a zero magnetic field was increased to 6930 A/cm 2 . The magnetic field dependence of J c (0.1 µV/cm criterion) was summarized as follows: 1660 A/cm 2 ( I ⊥ H , a - b plane ∥ H , 0.1 T), 900 A/cm 2 ( I ⊥ H , a - b plane ⊥ H , 0.1 T). We found that the grain boundaries were bonded strongly in the direction of alignment.