Flux pinning in high-Tc superconductive films

Magnetization measurements have been performed on c-axis oriented Y- and Gd-based superconductive films in a wide range of the temperatures T (4.2-85 K) and magnetic fields H (0-8 T) with H�� c-axis. The influence of flux creep on both the temperature dependence of critical current density Jcm and the scaling behavior of flux pinning force Fp has been discussed in detail. The experimental results show that Y and Gd films have different pinning mechanism. Flux pinning-force peaks in high fields are observed in Gd film at high temperatures and can be considered as evidence for collective pinning. ? 1995 Plenum Publishing Corporation.