Papers by Keyword: Ising Models

Abstract: In this paper we study within the Ising model a ferromagnet with annealed impurities in thermodynamic equilibrium with the lattice by the method of averaging over the exchange-interaction fields. We show that diffusion can significantly reduce the average critical concentration of "ferromagnetic" atoms and increase the Curie temperature. Also diffusion leads to the appearance of regions with high concentrations of ferromagnetic atoms on a background field with their low content.

Abstract: Phase transitions and critical phenomena are investigated within a two-sublattice model. In the framework of the random fields with the exchange interaction method the system of equations is obtained. It allows us to establish conditions under which magnetic phase transitions are possible. Critical concentration of ferromagnetic atoms which is necessary for the existence of ferromagnetic, ferrimagnetic and antiferromagnetic phases is determined.