PM-FM transition in a DE model
  We study paramagnetic - ferromagnetic transition due to exchange interaction between classical localized magnetic moments and conduction electrons. By solving the Dynamical Mean Field Approximation equations we find explicit formula for the transition temperature $T_c$ for arbitrary electron dispersion law, concentration and re lation between exchange coupling and the electron band width. We present the results of calculations of the $T_c$ for the semi-circular electron density of states. 
E. Kogan and M. Auslender