Phase transitions in Ising magnetic films and superlattices

We examine the phase transitions in Ising magnetic films and superlattices, within the framework of mean field theory. We derive, by the transfer matrix method, two general nonlinear equations for the phase transition temperatures of Ising magnetic films and superlattices, respectively. The equations can be applied to the films and superlattices with arbitrary exchange interaction constants and arbitrary layer number. Numerical results for phase transition temperatures as a function of exchange interaction constants are presented.