Spatially modulated magnetic structures in thin films

W. Selke, D. Catrein
Institut für Theoretische Physik, Technische Hochschule Aachen, D-52056 Aachen, Germany

M. Pleimling
Institut für Theoretische Physik, Universität Erlangen, D- 91058 Erlangen, Germany;
Laboratoire de Physique des Materiaux, Universite Henri Poincare Nancy I, F--54506 Vandoeuvre les Nancy Cedex, France


The axial next--nearest neighbour Ising (ANNNI) model is studied for thin films of up to L= 10 layers, with a distinct phase diagram for each film thickness. The systematics of the ordered phases, as obtained from mean--field theory, Monte Carlo simulations, and low temperature expansions, is discussed. Results are compared to those for the ANNNI model in the limit L going to infinity.