Exchange interaction and magnetic phase transition in layered Fe/Au superlattices

In order to study the finite-temperature properties of the layered Fe/Au superlattice, Monte Carlo (MC) simulations are carried out based on a Heisenberg model with the exchange parameters extracted from the ab initio total energies and a phenomenological anisotropy constant. It is argued that the Curie temperature is rather insensitive to the anisotropy and is essentially determined by the ab initio exchange parameters. Due to the reduced coordination number of the magnetic atoms at interfaces, the Curie temperature obtained by this ab initio-MC scheme decreases as decreasing of Fe layer thickness is governed essentially by Weiss'law. (C) 2001 Elsevier Science B.V. All rights reserved.