Fabrication and characterization of Bi2223/Ag tapes with interfilamentary oxide barriers for reducing AC losses

We prepared and characterized Bi2223/Ag tapes with interfilamentary oxide barriers for AC loss reduction in external AC magnetic field. Ca2CuO3, Al2O3, and SrZrO3 were selected as barrier materials. 20-30wt% Bi2212 were added to Ca2CuO3 and SrZrO3 powders to improve their deformation properties for cold working. The multifilamentary tapes with interfilamentary oxide barriers were fabricated with a conventional powder-in-tube method. The influence of introducing different oxide barriers on the final tape properties such as the phase formation in filaments, critical current density J(c) and its uniformity along a tape length, was evaluated. Based on the results of the preliminary studies, we determined the oxide materials for fabrication of barrier tapes with twisted filaments. AC losses in barrier tapes with twisted filaments were measured at 77 K in transverse AC magnetic field. The AC loss characteristic of the tape with barrier was compared to the one of the tape without barrier.