Interface disorder and layer transitions in Ising thin films

Abstract The disorder and layer transitions in the interface between an Ising spin‐1/2 film denoted ( n ), and an Ising spin‐1 film denoted ( m ), are studied using Monte Carlo simulations. The effects of both an external magnetic field, acting only on the spin‐1/2 film, and a crystal magnetic field acting only on the spin‐1 film, are studied for a fixed temperature and selected values of the coupling constant J p between the two films. It is found that for large values of the constant J p , the layers of the film ( n ), as well as those of the film ( m ), undergo a first order layering transition. On the other hand, the only disordered layer of the film ( n ) is that one belonging to the interface films ( n )/( m ), for any values of the crystal field Δ . We show the existence of a critical value of the crystal field Δ c , above which this particular layer of the film ( n ) is disordered. We found that Δ c depends on the values of the constant coupling J p between the two films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)