Phase diagram for the Anderson lattice model

We study the competition between the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida interaction in the framework of the Anderson lattice model with an extra intersite exchange term. By using an approximation based on an atomic expansion, we obtain, for the symmetric half-filled case, a phase diagram analog to the Doniach diagram for the Kondo lattice. The qualitative and quantitative progress in the description of experimental results for the cerium Kondo compounds with respect to previous approaches is discussed. We also calculate the specific heat which exhibits a two-peak structure as a function of temperature.