The effect of the time dependent angular distribution of the intergrain magnetic field on the transport critical current in Ag-(Bi,Pb)(2)Sr2Ca2Cu3Ox tapes

Changes in the energy dissipation of the tape form Ag-(Bi,Pb)(2)Sr2Ca2Cu3Ox conductor have been interpreted in terms of magnetic flux movement from, or into, the intergrain regions of the highly textured plate like grain structure. The time dependent increase or decrease of the transport critical current (I-c), originates from time dependent angular superposition of the current induced self field (H-SF), and external magnetic field [field cooling (H-FC) and zero-field cooling (H-ZFC)] at the intergrain regions. The existence of time dependent changes of I-c can be explained in terms of the time dependent flux redistribution in grains and grain boundaries caused by thermal relaxation processes. (C) 1996 American Institute of Physics.