Monte Carlo simulations on thin rare earth films: Preliminary data

We present Monte Carlo simulation data about Holmium magnetic thin film structures. As well known, this rare earth shows, at transition temperature TN, a helical order in the bulk phase. In contrast with the collinear ferromagnetic or antiferromagnetic thin films, recent experimental works have proven that the transition temperature TN(n) (n being the film thickness) depends on n only by an empirical relation. In order to study the behavior of these film structures, we consider a Heisenberg model with easy-plane single ion anisotropy and seven coupling constant (J0 in the plane and J1−J6 between plane of the Ho hcp structure), obtained by experimental neutron measurements.