Phase diagram for the Anderson lattice model

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