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

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 degreesC/cm was 4.4 x 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. (C) 2001 Elsevier Science B.V. All rights reserved.