Metastable characteristics in ferromagnetic TbPdIn and DyPdIn

Equiatomic ternary compounds, TbPdIn and DyPdIn, have been studied by means of DC magnetization, AC susceptibility, magnetic relaxation, specific heat and electrical resistivity measurements. The two compounds are ferromagnets below a transition temperature T_C = 74 K for TbPdIn and T_C = 38 K for DyPdIn with metastable magnetic properties, behaving as the irreversibility of the temperature dependence of magnetization below a characteristic temperature T_ir and the long-time magnetic relaxation behavior below T_C when changing the magnetic field at a constant temperature. DyPdIn shows the second phase transition at T_N = 23 K, caused by the antiferromagnetic coupling. For both compounds, the ground state is not a collinear ferromagnet, but some canted one with antiferromagnetic component. The observed metastable magnetic properties are discussed in terms of domain-wall pinning model. The complex magnetic structures in DyPdIn and TbPdIn are compared with those of isostructural DyNiAl and HoNiAl.