Magnetization steps in Pb1−xCexS at 20mK

Abstract The magnetization of Pb1−xCexS single crystals was measured at 20 mK and magnetic field upto 90 kOe. Magnetization steps from two types of pairs were observed. The first has an isotropic exchange interaction with J=−0.32 K. The second type of pairs gives a structured step which can be explained by an anisotropic exchange interaction. Cluster statistics suggests that both types are nearest-neighbor pairs.