Theory for the hysteretic properties of the low-field dc magnetization in type-II superconductors

We examine theoretically the following types of magnetization measurements of type-II superconductors: (1) zero-field cooled (ZFC), (2) field cooled with data collected on cooling (FCC), (3) field cooled with data collected on warming (FCW), and (4) remanent. In analyzing the irreversible behavior of the low-field dc susceptibilities, the important parameters are the critical current density, sample dimensions, and lower critical field. We point out that the irreversibility temperature is determined by the merging point of the FCC and ZFC, but not the FCW and ZFC, magnetization curves.