Spin - glass transition in Kondo lattice with quenched disorder
  We use the Popov-Fedotov representation of spin operators to construct an effective action for a Kondo lattice model with quenched disorder at finite temperatures. We study the competition between the Kondo effect and frozen spin order in Ising-like spin glass. We present the derivation of new mean-field equations for the spin-glass order parameter and analyze the effects of screening of localized spins by conduction electrons on the spin-glass phase transition. 
M.N.Kiselev and R.Oppermann (Institute for Theoretical Physics,   Wuerzburg University, Germany)