Step change in equilibrium magnetization across the second magnetization peak and the peak effect region of a weakly pinned low T_c superconductor, Ca_3Rh_4Sn_(13)

摘要

Isothermal magnetization studies in a low T_c type II superconductor, Ca_3Rh_4Sn_(13) (T_c ≈ 8.37 K), show abrupt step changes in the equilibrium magnetization lines across the second magnetization peak and the peak effect regions suggesting that both of these phenomena are first order phase transitions. We also observed two jumps in the equilibrium magnetization at two different temperature (or field) domains for a constant field (or temperature) in this low T_c superconductor.