INTERMEDIATE VALENCE - PHASE-DIAGRAM AND KONDO BEHAVIOR IN A SIMPLE-MODEL

We have studied an infinitely narrow band version of the Anderson Hamiltonian. Including a Coulomb repulsion between localized and band states in the mean field approximation, we have been able to describe metal-insulator phase transitions and different properties characteristic of intermediate valence in both phases. These include: non-integer occupation, specific heat, saturating static magnetic succeptibility and dynamical properties such as Mössbauer spectra and spin flip neutron spectra. We discuss for what range of values of the parameters some results can be reproduced by a narrow band version of the Kondo Hamiltonian. © 1979 Springer-Verlag.