Enhancement of transport critical current density in nano Cr _2O_3 added Ag-sheathed (Bi_(1.6)Pb _(0.4))Sr_2Ca_2Cu_3O_(10) superconductor tapes

摘要

Ag-sheathed (Bi_(1.6)Pb_(0.4))Sr_2Ca _2Cu_3O_(10) (Bi-2223) high temperature superconductor tapes with 0.1 wt% nano Cr_2O_3 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 (～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 pmax 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 Cr_2O _3 added tapes.