Hysteresis curves of the flux motion in YBa2Cu3O7-delta thin films with nanoscale pinning centers

摘要

Epitaxial YBa2Cu3O7-delta thin films were prepared by DC magnetron sputtering technique. The Y2O3 nanoprecipitates were evidenced the complete thickness. Magnetic hysteresis measurements using a SQUID based DC magnetometer were performed. From the M(H) curve we deduced the critical current density J(c) values function of magnetic field. The Kim and Bean critical state models were used for estimation of J(c).