Magnetic ordering and magnetocaloric effect in PrPdIn and NdPdIn

Magnetic, transport, thermal and magnetocaloric properties of the hexagonal ZrNiAl-type compounds PrPdIn and NdPdIn have been studied. The results indicate that both the compounds exhibit long-range ferromagnetic ordering with the transition temperature T_C=11.2 and 34.3 K, respectively. For NdPdIn, an additional phase transition occurs at T₀=18.3 K caused by the antiferromagnetic coupling. The magnetic entropy change of PrPdIn and NdPdIn, calculated from the magnetization data, shows a large peak around the temperature just above T_C suggesting the evident magnetocaloric effect. Below T_C, both samples show the irreversible temperature dependence of magnetization and the long time magnetic relaxation effect, which may be the consequence of the domain-wall pinning effect and/or the intrinsic magnetic frustration due to the non-collinear ferromagnetic spin structure.