Nanoparticles as flux pinning centre in bulk and Ag sheathed Bi1·6Pb0·4Sr2Ca2Cu3O10 high temperature superconductor tapes

Abstract

The enhancement of critical current density in Bi1·6Pb0·4Sr2Ca2Cu3O10 (Bi2223) superconductor in bulk and tape form through the addition of Cr2O3 (6·5 nm) and Fe3O4 (40 nm) nanoparticles is reported. The superconductor powders were prepared by using the coprecipitation technique. The powder in tube method was used to fabricate the Ag sheathed high temperature superconductor tapes with addition of various weight per cent of nanoparticle. The effects of these nanoparticles additions on the transition temperature Tc and transport critical current density Jc were studied. All nanoparticles added samples showed higher Jc compared to the non-added samples. When magnetic nanoparticles (Fe3O4) are employed, a smaller amount is required to optimise Tc and Jc. This study shows that nanoparticles can act as effective pinning centres leading to the enhancement of Jc in the Bi2223 system.