Ac-susceptibility of heavy-fermion superconductor CeRhSi₃ under pressure

We report the temperature dependence of the zero-field ac-susceptibility of CeRhSi₃ under several pressures. We have observed a clear difference between the onset temperature of superconducting transition T_c ^onset and main shielding temperature T_c ^main. T_c ^main approaches T_c ^onset with increasing pressure and merges at about 2.4 GPa at which the antiferromagnetism vanishes under zero field. In the temperatures between T_c ^onset and T_c ^main the decrease of _χ′ is quite small while _χ″ changes largely At T_c ^main, _χ′ drops and _χ″ peaks sharply as those of conventional superconductors. These results imply that CeRhSi₃ has two different types of pinning state in the superconductivity and the appearance of them is probably associated with the antiferromagnetic state.