Investigation of magnetic properties of 2223-BSCCO steel-reinforced tapes

Reinforcing multifilamentary Bi₂Sr₂Ca₂Cu₃Oy (2223-BSCCO) requires careful evaluation of magnetic losses and, in general, of the quantities related to the hysteresis loop (e.g., coercive field and residual magnetization). In this paper, the results of magnetic quantity measurements performed on superconductive tapes reinforced by both AISI 304 and AISI 316 stainless steel layers are discussed. It is shown that the former kind of steel has power losses higher than the latter. Therefore, from this point of view AISI 316 constitutes a better solution than AISI 304 to reinforce BSCCO-Ag tapes. Comparative measurements performed on the steel layer, the superconductor, and the reinforced tape, separately, allow the different contributions to the total magnetic loss to be singled out. In this way, a relationship between the induced voltages in one single steel layer, in a BSCCO-Ag tape without steel, and in the reinforced structure (BSCCO + 2 steel layers) is derived.