Enhanced transport critical current density of (Bi, Pb)-2223/Ag superconductor tapes added with nano-sized Bi2O3

Ag sheathed superconductor tapes with starting composition (Bi, Pb)-2223(Bi2O3)0.01 were prepared. Bi2O3 with average size 150 nm was used in this work. The Bi2O3 amount was chosen based on our initial study on nano-sized Bi2O3 added pellets which showed an optimal superconducting property for 0.01 wt% addition. Non-added tapes were also prepared for comparison. The tapes were investigated by X-ray diffraction method, scanning electron microscopy and transport critical current density, Jc measurements (30 K to 77 K). The influence of different sintering times (50, 100, and 150 h) on Jc under applied magnetic field (0-0.75 T at 77 K) parallel and perpendicular to the surface of the tapes was also investigated. Jc of added tapes was found to increase significantly as compared with the non-added tapes. The Bi2O3 added tapes sintered for 150 h exhibited the highest Jc at 30 K of 57,900 A/cm2 as compared with 19,400 A/cm2 for the non-added tapes sintered for 100 h. The improvements in flux pinning and connectivity between grains due to nano Bi2O3 addition led to the enhancement of Jc.