Ground-State Phase Diagram of a Model FCC Magnet with Modified RKKY Interaction

The ground-state phase diagram is studied for a diluted model magnet with FCC structure and modified Ruderman-Kittel-Kasuya-Yosida interaction. The modification consists in taking into account the exponential damping for the long-range interaction as well as the nearest-neighbors antiferromagnetic superexchange couplings. The existence of paramagnetic, ordered ferromagnetic and three distinct antiferromagnetic phases is shown. The stability areas of the phases upon the free-carriers concentration are investigated.