The Effect Of Magnetic Relaxation on Ac Susceptibility In Type-II Superconductors

In this paper, the study investigates the effect of magnetic relaxation on the ac susceptibility in type-II superconductors. To this end, the flux creep equation of ac response is deduced, and the characteristic relaxation time is modified. The relaxation effect is a key feature of flux creep. The results show that the change of the effective relaxation time directly affects the effective potential barrier and the approximate relaxation rate of the superconductor at a certain frequency when the critical current density and critical temperature are fixed, which in turn can cause significant changes in the imaginary part of the AC susceptibility. The results are expected to contribute to a better understanding of the flux dynamics of superconductors from a theoretical perspective.