THEORY FOR THE HYSTERETIC PROPERTIES OF THE LOW-FIELD DC MAGNETIZATION IN TYPE-II SUPERCONDUCTORS

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