Incommensurate magnetic order in rare earth and transition metal compounds with local moments.

Within the framework of thes-d(f) exchange model in the mean-field approximation for square, simple cubic, body-centered and face-centered cubic lattices, the formation of a ferromagnetic, spiral, and commensurate antiferromagnetic (AFM) order is investigated. The possibility of the formation of inhomogeneous states (magnetic phase separation), which necessarily arises during first-order phase transitions in the electron filling parameter, is taken into account. The saturation of the AFM and spiral states is studied depending on the parameters of the model. The results obtained include a rich variety of magnetic structures and phase transitions, allowing the interpretation of magnetic properties of semiconducting and metallic systems containing magnetic atoms.