Microstructures and J_c-B Characteristics of Ag-Sheathed Bi-Based Superconducting Wires

Abstract

We prepared silver-sheathed BiPbSrCaCuO wires by the powder-in-tube method. Maximum critical current densities at 77.3 K were 5.4×10 4 A·cm -2 in a zero magnetic field, 4.2×10 4 A·cm -2 at 0.1 T and 1.2×10 4 A·cm -2 at 1 T. At 77.3 K, as the J c improves, the history effects decrease. J c and J c - B enhancements are due to the decrease and dispersion of nonsuperconducting phases, and to grain boundary improvements.