Non-Fermi-liquid behavior in Kondo lattices induced by peculiarities of magnetic ordering and spin dynamics

A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior can be naturally connected with the regime which is marginal between the regions of strong coupling (Kondo lattice) an d weak coupling ("usual" magnets). For complicated magnetic structures with several magnon branches, this regime occurs naturally between two critical values of the bare s-f coupling constant. Another kind of a NFL-like state (with different critical exponents) can occur for simple antiferromagnets with account of magnon damping, and for paramagnets, especially with two-di mensional character of spin fluctuations. The mechanisms proposed lend to s ome predictions about behavior of specific heat, resistivity, magnetic susc eptibility, and anisotropy parameter, which can be verified experimentally. In particular, the Wilson ratio is predicted to weakly increase with lower ing temperature.