Weak ferromagnetism and multiple metamagnetic transitions in the non-centrosymmetric tetragonal compound CePdSi₃

We have succeeded in growing single crystalline samples of CePdSi₃ with the BaNiSn₃-type non-centrosymmetric structure. Specific heat, magnetic susceptibility, and magnetization measurements were carried out, which revealed three successive magnetic transitions at T_I = 4.85(5) K, T_II = 2.78(5) K, and T_III = 2.30(5) K at zero field. Below T_II, a weak ferromagnetic component was observed, indicating a canted antiferromagnetic ground state in CePdSi₃. The observed large magnetic anisotropy in CePdSi₃ was explained in terms of a simple crystalline-electric-field model. From the magnetization measurements, we identified five (three) magnetic states in the H-T phase diagrams for the H || [100] ([001]) direction. Interestingly, only three magnetization steps were observed for H || [110], suggesting the existence of the in-plane magnetic anisotropy in CePdSi₃. We discuss a possible nature of the complex magnetic properties of CePdSi₃.