Barrier-to-pinning crossover of the AC-susceptibility in thin-film superconductors

The dependence of higher harmonics of a magnetic susceptibility of narrow s uperconducting films on the amplitude of applied magnetic field is theoreti cally investigated. The effect of sign change for the third harmonics of AC -susceptibility is predicted when dominant contribution to hysteresis chara cteristics due to edge barrier is replaced by that due to bulk pinning. The condition of the barrier-to-pinning crossover of the AC susceptibility is determined for the Bean critical state model. (C) 2000 Elsevier Science B.V . All rights reserved.