Magnetic states in the itinerant magnets

A new classification of magnetic materials using their degree of itinerancy is proposed. The classification produced a variety of magnetic states near the magnetic instability point. Several types of itinerant magnets are determined and their corresponding analogs among known systems are identified. We discuss the degree of the short-range magnetic order in such systems and establish a criterion for its appearance. The appearance of a smooth transition from the localized (Heisenberg) magnets to the itinerant (Stoner) ones is demonstrated for the intermediate type of magnets. Realistic calculations of magnetic states developing at finite temperatures in several typical ferro- and antiferromagnetic itinerant systems (Ni, Co, Cr, and so on) confirm the results of the proposed model and demonstrate new and unusual transformations of magnetic behavior in such systems.