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

Ag-sheathed (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (Bi - 2223) high temperature superconductor tapes with 0.1 wt% nano Cr2O3 were fabricated using the powder-in-tube method. The effects of intermediate rolling and sintering temperature on the transport critical current density (J(c)) under self-field and applied magnetic field were studied. The X-ray patterns showed a dominant Bi - 2223 phase (similar to 80%). A decrease in J(c) in applied magnetic field, parallel or perpendicular to the sample wide surface was observed for all tapes. Intermediate rolling improved the self-field J(c) (T = 77 K) of the tapes by 25%. Both J(c) versus applied field curves and normalized pinning force density F-p/F-p (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 J(c) was observed in the nano Cr2O3 added tapes