Reduction of AC losses applying novel resistive interfilamentary carbonatebarriers in multifilamentary Bi(2223) tapes

Hysteresis losses and coupling losses, a main component of the AC losses in Bi(2223) tapes, can effectively be reduced by enhancing the resistivity of the matrix material between the filaments and applying a filament twist. S ince through alloying the sheath, as using AgAu(8 wt.%), the resistivity ca n only be raised by a factor < 10 (77 K), a new conductor configuration wit h a quite novel composite matrix having resistive SrCO3 barriers inside the Ag matrix between the filaments was developed. These new barriers, a cheap and commercial material, withstand the tape annealing, do not react with t he superconductor, sinter dense and have a good bonding to Ag. Applying two different preparation techniques for 19 filament prototype tapes, critical current densities up to 20.7 kA cm(-2) were achieved. We report on tape pr eparation, the effect on the phase texture and the superconducting properti es of such barrier tapes. (C) 1998 Elsevier Science B.V. All rights reserve d.