Extension of Bean's model for high-T_c superconductors

Abstract

High-T_c superconductors have critical current densities J_c that decay sharply with increasing magnetic fields. We solve Bean's model for J_c decaying exponentially with H and obtain virgin magnetization curves and hysteresis loops. We show that the shape of the hysteresis loop can be altered significantly if the maximum field applied is not large enough, and we explain discrepancies between various magnetization data reported in the literature.