Flux patterns of multifilamentary Ag-sheathed (Pb,Bi)2Sr2Ca2Cu3O10+δ tapes

Flux patterns of multifilamentary Ag-sheathed (Pb,Bi)(2)Sr2Ca2Cu3O10+delta tapes comprising 19 filaments are visualized by means of magneto-optic imaging. In low fields, the shielding currents are seen to flow mainly in the outermost filaments. With increasing external magnetic field, the inner filaments also contribute to the current flow. To compare the local flux distribution with the integral magnetization values, magnetization loops are measured by a SQUID magnetometer on the same sample following the fields used in the magneto-optic imaging (+/-120 mT) and covering fields up to +/-5 T at various temperatures. The magnetization loops also reveal that the multifilamentary tapes show the anomalous position of the central peak, but always less pronounced than in monofilamentary tapes. (C) 1998 American Institute of Physics.