Generalized mean-field theory for metals and semiconductors with magnetic impurities

Abstract

Random systems of magnetic moments positioned in cites of a crystal lattice and interacting via RKKY- or Bloembergen–Rowland-type interaction are considered in the framework of generalized mean-field theory (GMFT) based on calculating and analyzing distribution functions F ( H ) of random local magnetic fields H. For concentrated systems (where the random local field is produced by a number of interacting magnetic moments), the function F ( H ) turns out to be Gaussian one and all information about the system is contained in two parameters of that distribution only—it's width and maximum position. For rarefied systems (where the average distance between interacting moments is comparable with or larger than the interaction length), distribution functions are essentially non-Gaussian. GMFT has been applied for calculating the magnetic state of metals and semiconductors diluted with magnetic impurities.