Thermally activated flux motion under a distribution of activation energies in high T-c superconductors

Within a thermally activated flux motion model and assuming a distribution of barriers, we derive exact closed form expressions for various parameters for magnetic relaxation in high T-c superconducting material. In particula r, we introduce a new parameter S* proportional to S, the normalized logari thmic decay of magnetization, and show that S* is a monotonically increasin g function of temperature. Published by Elsevier Science B.V. All rights re served.