INVESTIGATION OF HYSTERESIS AND TRANSPORT CRITICAL-CURRENT UNDER FIELD CYCLE FOR BI-BASED MULTIFILAMENTARY TAPES

The transport properties of Hi-based multifilamentary tapes on magneti c field have been studied. The tapes were fabricated by powder-in-silv er tubing technique followed by appropriate sintering. The hysteretic behavior of transport critical current of the tapes with bending strai n has been investigated. The experimental data are obtained at 77 K un der field cycling from 0 to 1000 G to 0. The critical current density under a field does not vary when bending strain is smaller than a crit ical bending strain, and then decreases gradually with increasing bend ing strain. The normalized values are unaffected by bending strain up to 1.31%. The remnant magnetic filed H-m associated with the flux pinn ing force is obtained by an empirical expression, which is similar to generalized critical state model. The H-m is almost a constant for all bending strain. This observation indicates that the intrinsic pinning properties are not varied with bending strain.