AC Loss Characteristics in Bi2223/Ag Tapes With Interfilamentary Oxide Barriers for Filament Decoupling

In this paper, we prepared Bi2223/Ag tapes with interfilamentary oxide barriers for filament decoupling and also for reducing AC losses under AC external magnetic field. To suppress the side effect on Bi2223 phase formation inside the filaments and superconducting properties in final tapes by introducing oxide barriers, we selected Ca₂CuO₃ as barrier materials. In addition, the 30 wt% Bi2212 powders were mixed into Ca₂CuO₃, to improve their deformation properties for cold working such as drawing and flat rolling. The mixtures of Ca₂CuO₃ and Bi2212 were introduced around the twisted Bi2223 filaments. AC losses in barrier tapes under parallel transverse magnetic field were measured at 77 K, and compared with the several analytical models. Based on the results, the effect of barrier introduction on the AC loss characteristics in twisted multifilamentary tape is discussed.