Phase diagrams of Kondo alloys

Abstract

We analyze the ground state phase diagrams of the Kondo alloy model (KAM) as a function of Kondo coupling (JK), electronic band filling (nc) and magnetic impurity concentration (x). We use DMFT/CPA method to treat the disorder and the inter-site electronic exchange correlations along with mean-field (MF) approximations to decouple the Kondo interaction. Here, we generalize “Doniach-like” phase diagrams of the periodic Kondo lattice (x=1) to Kondo alloys. We consider the competition between the paramagnetic Kondo phase (K) and purely ferromagnetic (F) or staggered antiferromagnetic (AF) ordered phases. Our phase diagrams are consistent with various experimentally obtained phase diagrams for alloys like CexLa1-xPt2Si2, CexLa1-xNi2Ge2, CexLa1-xRu2Si2, CexLa1-xPd2Si2, or CexLa1-xCu2Ge2.