Current distribution in Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-(delta)/ disk-shaped thin film by scanning Hall probe measurements

We have measured the shielding and trapped (remanent) magnetic field profiles both perpendicular (H/sub z/(r)) and parallel (H/sub r/(r)) to the planes of a zero-field-cooled disk-shaped YBCO thin film. H/sub z/(r) and H/sub r/(r) were obtained using transverse and radial scanning Hall probes at various temperatures ranging from 30 K to 70 K and at small magnetic fields up to 750 G. The current distributions in the samples were inferred from a direct comparison of our experimental profiles to the theoretical ones obtained using the critical state models by Mikheenko et al. (1993) and Zhu et al. (1993). The models are in good agreement with the experimental trapped field profiles; however field dependence of the current should be taken into account for the shielding profiles.