Fast magnetization relaxation and flux creep in a highly textured thin films of YBa2Cu3O7
Résumé
We report investigations of the hysteresis cycle and the associated relaxation of the critical current of highly textured YBa2Cu3O7-δ thin films. Strong deviations from linear logarithmic law (lnt) are observed for all fields and temperatures. Three distinct pinning regimes are identified as H increases from zero to H≈70kG. The derivative dM/dH exhibits a small but abrupt change at H≈30kG for T≈55K.