Complex magnetic behavior in Ce5Rh4Sn10 doped with La

Abstract

Ce5Rh4Sn10 is known as a heavy-fermion antiferromagnet with magnetic-ordering temperature T N2 = 4.3 K. We report a new antiferromagnetic phase transition at T N1 = 1.4 K. In the series of Ce1−x La x Rh4Sn10 compounds both magnetic phase transitions at T N1 and T N2 shift towards lower temperatures. For Ce3La2Rh4Sn10 and Ce3.5La1.5Rh4Sn10 we found only one transition. In the temperature region T N1<T<T N2, the magnetization M measured as a function of magnetic field H exhibits a large jump at very low fields of ∼0.03 T with a very small hysteresis loop. This abnormal behavior could be due to spin-flip transitions. Thermodynamical properties of the series of Ce1−x La x Rh4Sn10 compounds are discussed in terms of the antiferromagnetic Kondo lattice.