Improvement of the critical current density in the silver sheathed Bi-Pb-Sr-Ca-Cu-O superconducting tape

Abstract

The critical current density (Jc) at 77 K and in 0 T of more than 3000 A/cm2 has been obtained in the silver sheathed Bi-Pb-Sr-Ca-Cu-O tape fabricated by the combination process of sintering and intermediate cold working. The decrease of the Jc with increasing magnetic field is much smaller in the tape prepared by this process than that prepared by sintering only. The improvement of the Jc is attributed to the improvement of the coupling between the grains of the high Tc phase. The process enhances the formation of the high Tc phase and produces a highly oriented grain structure. These are considered to be responsible for the large improvement of the coupling.