The diffusion of the vortices in high T-c thin film microbridges: Model and results

We have previously proposed a model for the flux creep regime of the vortic es in superconducting thin film microbridges in which a bias current flows. In the first part of the paper this model is summarized and we show how ph ysical quantities which are relevant to estimate the importance of vortex p inning in the samples can be determined. Then, the effect of a low applied magnetic field on the modulation of the critical current of the microbridge s is discussed and we show how this type of measurements can give additionn al information on the vortex motion in the samples and allows to determine their superconducting thickness and penetration depth as a function of temp erature.