Ab initio calculations for layered Fe/Au(001) superlattices with a set of collinear spin configurations are performed by means of the self-consistent full-potential linearized augmented-plane-wave method under the generalized gradient approximation. To study the finite-temperature magnetism of such superlattices, 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 governed essentially by Weiss’ law. These results are discussed in connection with recent experimental and theoretical studies.

• Received 22 December 1999

DOI:https://doi.org/10.1103/PhysRevB.62.3354