Frequency dependence of ac magnetic response in type-II superconductors

Abstract The ac magnetic response in type-II superconductors was analyzed on the basis of flux creep theory. A modified model was proposed to describe the variation of current density in a sample immersed in an alternating field, which simultaneously took into account the sweeping applied field and the flux creep inside the sample. The frequency dependent ac susceptibility of a textured YBa 2 Cu 3 O 7 bulk sample was measured and explained in this model. Also discussed was the relation between our model and other models that appeared in literature.