Critical Current and AC Loss of DI-BSCCO Tape Modified by the Deposition of Ferromagnetic Layer on Edges

Modification of local magnetic field with the help of a ferromagnetic layer could be utilized to improve the performance of multifilamentary Bi-2223/Ag tapes. We investigated the case of the horseshoe-shaped cover on the tape edges, characterized by layer thickness and total length. Numerical simulations have been carried out to find the critical currents of tapes with different covers. According to the indications obtained from these calculations, samples with covered edges have been prepared with the primary aim of increasing the self-field critical current. We observed up to 7% enhancement of this quantity. AC loss was also investigated theoretically and experimentally in a case of applied ac transport current or ac magnetic field applied perpendicular to the tape wide surface. Reduction of both the transport loss and the magnetization loss has been observed. Good agreement is obtained between the experimental data and the calculations.