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, J(c) measurements (30 K to 77 K). The influence of different sintering times (50, 100, and 150 h) on J(c) under applied magnetic field (0-0.75 Tat 77 K) parallel and perpendicular to the surface of the tapes was also investigated. J(c) 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 J(c) at 30 K of 57,900 A/cm(2) as compared with 19,400 A/cm(2) 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 J(c). (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.