INTERPLAY BETWEEN HEAVY FERMIONS AND CRYSTAL-FIELD EXCITATION IN KONDO LATTICES - LOW-TEMPERATURE THERMODYNAMICS AND INELASTIC NEUTRON-SCATTERING SPECTRA OF CENISN

The microscopic theory of interaction between the heavy fermions and t he crystal-field excitations in Kondo lattices is presented. It is sho wn that the heavy-fermion spectrum scaled by the Kondo temperature T-K can be modified by the crystal-field excitations with the energy Delt a(CF) provided the inequality Delta(CF)<T-K is realized. On the base o f the general description of the excitation spectrum, the detailed qua litative and quantitative explanation of anisotropic inelastic neutron scattering spectra and low-temperature specific heat of orthorhombic CeNiSn is given. The theory resolves the apparent contradiction betwee n the metallic conductivity and the gapwise behavior of thermodynamic properties and spin response of CeNiSn at low temperatures.