Magnetic properties of RPdIn (R = Gd-Er) compounds

AC susceptibility and DC magnetization measurements were performed for the RPdIn (R = Gd-Er) compounds both in the paramagnetic and in the ordered state. In opposite to GdPdIn, which is a ferromagnet (T-c = 102 K), the other samples show a complex ferrimagnetic behavior with the additional transition at T-1 < T-c. In the high-temperature phase (for T-1<T<T-c), a ferromagnetic interaction dominates, while in the low-temperature phase (for Tless than or equal toT(1)) antiferromagnetic interactions with the magnetocrystalline anisotropy, especially strong for TbPdIn, come into play. The ordering temperatures are T-c = 70, 34, 25 and 12.3 K for Tb-, Dy-, Ho- and ErPdIn respectively, while transition temperatures are T-t = 6, 14 and 6 K for Tb-, Dy- and HoPdIn respectively. TbPdIn reveals an additional transition at 27 K connected with the intermediate ferrimagnetic phase. The critical fields for the magnetization process of the low-temperature phase are high (52 and 150 kOe for TbPdIn and 32 kOe for DyPdIn at T = 4.2 K) yet these values decrease remarkably with increasing temperature. Results of the study are compared with magnetic and neutron diffraction data hitherto available. We state that irreversibility of the zero-field cooled-field cooled magnetization is not connected with the spin-glass phase claimed elsewhere. (C) 2002 Elsevier Science B.V. All rights reserved.