Study of magnetic ordering in a multisublattice Ising model in terms of static fluctuation approximation

Abstract

In terms of the static fluctuational approximation previously developed by the authors, a closed set of equations was found for finding all necessary thermodynamic characteristics (including the calculation of two-particle correlation functions) of a multisublattice Ising model with an arbitrary interaction between spins over the entire temperature range. Magnetic ordering on a simple-cubic magnetic lattice is investigated with allowance for the nearest and next-nearest neighbors. Closed equations were obtained for binary correlation functions of a given system.