KONDO EFFECT, SPIN DYNAMICS AND MAGNETISM IN ANOMALOUS RARE-EARTH AND ACTINIDE COMPOUNDS .2. THE PROBLEM OF THE GROUND-STATE

The problem of magnetic ordering in Kondo lattices is discussed. Criteria of ferro- and antiferromagnetism in the mean-field approximation for the s - f exchange model are obtained. In the case of a constant bare DOS, the saturated Kondo ferromagnetic solution is energetically stable at small intersite interactions J. The role of spin-fluctuation corrections at low T < T(K) in the building up the low-energy scale and the ground state magnetization is considered. Renormalization of spin-fluctuation frequencies at T > T(K) is calculated. A possible picture of the formation of magnetism is presented starting from the high-T limit.