Revisited Doniach diagram: Influence of short-range antiferromagnetic correlations in the Kondo lattice

The Kondo lattice model including nearest-neighbor magnetic exchange interactions is studied here in a mean-field approximation describing both the Kondo state and the intersite magnetic correlations. In the case of antiferromagnetic correlations, our model yields a decrease of the Kondo temperature compared to the one-impurity value, giving, therefore, a ''revisited'' version of the Doniach diagram with a rather flat Kondo temperature in the nonmagnetic case, as observed in several cerium compounds. Our model shows also that short-range magnetic correlations can appear at a temperature clearly larger than the Kondo temperature, as observed in compounds such as CeCu6 or CeRu2Si2. [S0163-1829(97)04642-0].