Ground-state magnetic phase diagram of the ferromagnetic Kondo-lattice model

The magnetic ground-state phase diagram of the ferromagnetic Kondo-lattice model is constructed by explicitly calculating internal energies of all possible bipartite magnetic configurations of the simple cubic lattice. This is done in one, two, and three dimensions for a local moment of S=3/2. By assuming saturation in the local-moment system we are able to exactly treat all appearing higher local correlation functions within an equation of motion approach. A simple explanation for the obtained phase diagram in terms of bandwidth reduction is given. Regions of phase separation are determined from the internal energy curves by an explicit Maxwell construction.