TRANSPORT RELAXATION AND INTRAGRANULAR FLUX CREEP IN POLYCRYSTALLINE YBA2CU3O7-X

The pinning energies (U0) of granular YBa2CuO7-x samples in the presence of a transport current were estimated by measuring the voltage relaxation in the classical four-probe arrangement under a range of different measuring conditions and using different criteria to calculate U0. The resulting values agree with the ones determined from the magnetization decay, performed on the same samples through vibrational sample magnetometry, and do not show a dramatic dependence on the measuring conditions. Although some basic questions are still open, these results suggest that the transport relaxation technique may constitute an alternative for the estimation of the pinning energy in granular superconductors.