Behaviour of Thin Magnetic Films at Low Temperatures

Abstract

The problem of the analysis of low temperature magnetization is exposed in detail. The application of exact Bose representation of spin operators to the bulk ferromagnets is justified. By means of this representation the magnetization of ultrathin films was analysed. It turned out that thin films magnetization contains exponentially small terms characterized by Dyson's functions even in harmonical approximation. The main conclusions of this work are that magnetic lattice of thin film is more rigid than the macroscopic lattice and that the autoreduction process (the three layer film divides onto three two layer subfilms) takes place in the film.