Microstructure and superconducting properties of Bi-2212/Ag tapes fabricated using melt-solidification under a temperature gradient

Abstract

We fabricated Bi-2212/Ag composite tapes by applying a melt-solidification process under a temperature gradient. We used a tube furnace with a temperature gradient for the heat treatment. The critical current density ( J c) of the tape fabricated under a temperature gradient of 1.5°C/cm was 4.4×10 5 A/cm 2 at 4.2 K under 10 T. This J c value was much higher than the J c value of the tapes fabricated by using the conventional melt-solidification process. We clearly observed quadruple rotation symmetry peaks in the (1 1 5) pole figure of Bi-2212 near the Ag substrate. These results show that the in-plane textured Bi-2212 oxide was obtained near the oxide/silver interface of the Bi-2212/Ag tape. J c enhancement was achieved due to this in-plane texturing together with the improvement of the c-axis grain alignment.