Transport currents along c-axis and (a,b) planes in YBCO single domain materials. Critical current densities and normal-superconducting transitions

High transport currents along the (a,b) planes and along the c-axis have been measured in pulsed current of different pseudo-frequencies. Self field losses and transport current of 8000 A (20 000 A cm(-2)) have been measured in Y1Ba2Cu3O7-delta bars textured by the melting zone technique. Critical currents as high as 500 A (90 000 A cm(-2)) along the (a,b) planes or 3000 A (7500 A cm-2) along the c-axis have been measured. For both orientations, the transition from the normal state to the superconducting state has been observed. Electric field of 1000 V m(-1) and study of the superconducting state recovery are reported. (C) 1998 Elsevier Science S.A. All rights reserved.