Magnetic Order in TbPdIn

Abstract

TbPdIn belongs to a large family of ternary RTX (R = rare earth, T = transition metal, X = p-metal) compounds crystallizing in the hexagonal ZrNiAl-type structure. Several contradictory results have been reported concerning the magnetic properties of TbPdIn. All the previous studies showed clearly that TbPdIn orders magnetically below Tord = 66 K, but the nature of the ordered state was unclear. A possible spin-glass state, which could arise from the spin frustration, was first speculated from the temperature dependence of zero-field-cooled and field-cooled magnetization [1]. On the other hand, powder neutron diffraction measurements revealed a definite 3D magnetic structure described by the (0, 0, 0) propagation vector [2]. The details of the magnetic structure however were not determined from the powder pattern. Further magnetization and susceptibility studies corroborated the long-range magnetic order in TbPdIn [3, 4], and the magnetization data reported in Ref. [4] indicated furthermore additional magnetic phase transitions at 27 and 6 K, previously not reported in other studies. These transitions were tentatively related to the weak magnetic reflections observed in the neutron powder pattern beside the main magnetic reflections [2]. The unresolved details of the magnetic structure and disagreement between different bulk measurements led us to perform a detailed investigation by new powder neutron diffraction and single-crystal neutron Laue diffraction.