Critical currents in Bi-Sr-Ca-Cu-O superconductors up to 33 T at 4.2 K

The I-V curves of Bi-Sr-Ca-Cu-O superconductors were measured in DC magneti c fields, oriented both parallel and perpendicular to the tape surface, up to 33 T, 4.2 K, in resistive magnets at the National High Magnetic Field La boratory. This paper presents the experimental set-up, results of critical current measurements, and an analysis of the obtained I,(B) curves in terms of strongly and weakly linked current paths. A distinct double-step behavi or is observed for field perpendicular to the tape surface. The scaling beh avior of the applied field with its component perpendicular to the ab-plane , and the implied average grain-misalignment angle, is investigated.