Microstructure, resistivity and critical currents of Ag-Bi/Pb(2223) tapes

The temperature and field dependences of critical current density, j/sub c/, in Ag-Bi/Pb(2223) tapes, prepared by the standard powder-in-tube method, have been measured between 4.2 K and 110 K in magnetic fields up to 15 T. The j/sub c/'s reproducibly reached values up to 20000 A/cm/sup 2/ at 77.35 K in zero magnetic field. After stripping or etching away the Ag-sheath, the microstructure of the superconductor core has been investigated by SEM, EDX and X-ray diffraction. On etched samples the resistance of the Bi(2223) filament has been measured. A value below 500 mu Omega -cm has been found for the resistivity at 130 K. >