THE SPECIFIC-HEAT COEFFICIENT AND THE COHERENCE TEMPERATURE FOR THE KONDO LATTICE SYSTEM

By a finite-temperature approach of the Green-function decoupling approximation the appearance of a peak gamma //m//a//x in the Kondo-lattice specific-heat coefficient is shown to result from the stabilization into the coherent state by the formation of a pseudogap at the Fermi level. This takes place at the coherence temperature T//m//a//x given by gamma //m//a//xT//m//a//x approximately 0. 6 J/mole K, which becomes approximately 0. 1 T//K for the Ce compounds in agreement with experiment (T//K the Kondo temperature).