Angular Dependence of Flux Pinning in High-T_c Superconductor Thin Films and Superconductor-Ferromagnetic Heterostructures

摘要

We report on the results of measurements of the angular dependence of magnetization of high-T_c superconducting YBa_2Cu_3O_(7-#delta#) and La_(1.85)Sr_(0.15)CuO_4 thin films and superconducting/ferromagnetic YBa_2Cu_3O_(7-#delta#)/Nd_(0.67)Sr_(0.33)MnO_3 superlattices. We compare our present results to our results, previously obtained for YBa_2Cu_3O_(7-#delta#) and Bi_2Sr_2CaCu_2O_8 single crystals. We discuss the influence of the presence of Nd_(0.67)Sr_(0.33)MnO_3 sublayers in YBa_2Cu_3O_(7-#delta#)/Nd_(0.67)Sr_(0.33)MnO_3 superlattices on the critical temperature, flux pinning, and the critical field for the first vortex penetration.