ENHANCEMENT OF TRANSPORT CRITICAL CURRENT DENSITY IN NANO Cr2O3 ADDED Ag-SHEATHED (Bi1.6Pb0.4)Sr2Ca2Cu3O10 SUPERCONDUCTOR TAPES

Abstract

Ag -sheathed ( Bi 1.6 Pb 0.4) Sr 2 Ca 2 Cu 3 O 10( Bi –2223) high temperature superconductor tapes with 0.1 wt% nano Cr 2 O 3 were fabricated using the powder-in-tube method. The effects of intermediate rolling and sintering temperature on the transport critical current density (Jc) under self-field and applied magnetic field were studied. The X-ray patterns showed a dominant Bi –2223 phase (~80%). A decrease in Jc in applied magnetic field, parallel or perpendicular to the sample wide surface was observed for all tapes. Intermediate rolling improved the self-field Jc(T=77 K ) of the tapes by 25%. Both Jc versus applied field curves and normalized pinning force density Fp/Fp max versus applied field curves showed that the pinning strength was significantly enhanced with thermo-mechanical treatments. SEM micrographs showed improvements in the grain alignment of tapes with intermediate rolling. Enhancement in Jc was observed in the nano Cr 2 O 3 added tapes.