Magnetic behaviour of RPdSb (R = rare earth) compounds

Magnetic susceptibility measurements have been carried out on the equiatomic ternary compounds. RPdSb (R = La to Tm), in the temperature range of 4.2-300 K and in various applied fields between 500 Oe and 6 kOe. The compound CePdSb orders ferromagnetically with ordering temperature T_M of about 17 K while NdPdSb, SmPdSb, EuPdSb and GdPdSb order antiferromagnetically with Néel temperature T_N of 11, 18, 13 and 17 K, respectively. All other compounds are paramagnetic in the temperature range investigated. The ordering temperatures of these compounds do not follow De Gennes scaling. The compound NdPdSb shows a metamagnetic transition at an applied field of ≅ 2 kOe at 4.2 K. The electrical resistivity of CePdSb shows a broad maximum around 150 K and an In(T) behavior at high temperatures, suggesting the presence of crystalline fields and Kondo effect.