A local Fermi liquid theory of intermediate valence systems

A non-interacting local Fermi liquid theory applicable to Ce, Sm, Eu and Yb metallic intermediate valence materials is presented. The induced density of states of a given rare earth ion is taken as the Lorentzian appropriate for a rare earth ion impurity, for which the justification is tentatively discussed. The degeneracy of the resonance is that of the magnetic configuration of the ion. The results are applied to the f occupation, susceptibility and specific heat. A relationship existing in the literature between the zero temperature susceptibility and linear coefficient of specific heat follows exactly from the present very simple theory. The results are compared with a range of experimental data.