Fabrication and properties of Ag-Bi2223 tapes with resistive barriers for filament decoupling

In this paper, we prepared the Bi2223 multifilamentary tapes with Ca2CuO3 + Bi2212 as interfilamentary resistive barriers to suppress the electromagnetic coupling among the filaments under AC external magnetic field. The tapes with thin barrier layers of Ca2CuO3 + 30 wt% Bi2212 around the filaments were prepared by using a standard powder-in-tube (PIT) method. The outside surface of monocore Ag-sheathed rods was coated by barrier materials. Then, the several coated monocore wires were stacked and packed into another Ag or Ag-Mg alloy tube. The packed tube was drawn and rolled into tape shape. The tape was subsequently sintered to form Bi2223 phase inside filaments. For the characterization of tapes, X-ray diffraction measurements were performed to investigate the phase formation inside the filaments. The uniformity of transport properties (Jc) for barrier tapes were evaluated on the order of several metre lengths and compared with the result for the tapes without barriers. Finally, AC loss characteristics under AC parallel transverse magnetic field were investigated to examine the effect of introducing the barriers on the filament decoupling