Fabrication and properties of Ag-sheathed Bi2223 tapes with Sr6V2O11 oxide barriers between filaments

We prepared Ag-sheathed Bi2223 multifilamentary tapes with and without a layer of Sr6V2O11 (SVO) barrier outside and inside each filament. The SVO barrier layers have no bad effects on the critical current density J(c) of the tapes. Especially, J(c) increases obviously in the tapes coated with SVO layers both inside and outside each filament. This can be due to the enhancement of Bi2223 phase formation by the reaction of the inside-coated SVO with Bi-based oxide core. These results suggest that even if an Ag-sheath of each filament is broken and the barrier SVO reacts with the Bi-based oxide core, the reaction has no bad effect, rather a good effect, on J(c). SVO will be one of the important candidates for barriers. (C) 2000 Elsevier Science B.V. All rights reserved.