Properties of Pb-doped Bi-Sr-Ca-Cu-O superconductors prepared by a hot-press method

Pressure effect during sintering (hot pressing) on the superconducting properties, focusing particularly on the critical current density J c , has been studied for the high- T c -phase Pb-doped Bi-Sr-Ca-Cu-O system. The properties are compared with those for the samples before the pressing or with intermediate-pressing at room temperature. The transport J c observed by resistive transition measurement at 77.3 K was 7,000 A/cm 2 at H =10 Oe for the hot-press sample, 6,260 A/cm 2 for the intermediate pressed sample at H =0 and around 500 A/cm 2 for the nonpressed one at H =0. The magnetic hysteresis loops were measured at 5 K and 77.3 K, and the hot-pressed sample showed larger hysteresis than that for the intermediate-pressed one.