Unusual magnetism of the Kondo lattice
Institute of Metal Physics, Ural Division of the Russian Academy of Sciences, ul. S Kovalevskoi 18, Ekaterinburg, 620219, Russian Federation
A review is given of the experimental situation and theoretical views concerning unusual magnetic ordering in dense Kondo 4f- and 5f-systems, including the recently investigated ternary systems based on cerium, ytterbium, and actinides. This unusual ordering is characterized by a small magnetic moment and exhibits features typical of both localized-spin and itinerant-electron magnets. Particular attention is paid to ferromagnetic systems and the competition between different types of magnetic order. The perturbation theory method, renormalization group approach and the auxiliary pseudofermion representation are considered as tools for describing the formation of the Kondo lattice ground state. The problem of non-Fermi liquid behavior is considered.