MAGNETIC RESPONSE OF DISK-SHAPED YBA2CU3O7-DELTA THIN-FILM TO A PERPENDICULAR MAGNETIC-FIELD

Magnetic measurements have been performed on a disk shaped YBa2Cu3O7-d elta thin film in a perpendicular field. The critical state model deve loped by Mikheenko and Kuzovlev and Zhu et al. is extended to analyze the demagnetizing effects of the film. Using the field-dependent criti cal current density through the two-current model, the virgin magnetic moment as a function of the applied field and the hysteresis loops at several temperatures can be well fit by the extended model. The curre nt density profiles and the flux density profiles of the film have bee n obtained and discussed.