Critical behaviour of magnetic thin film with Heisenberg spin-S model

The magnetic properties of a ferromagnetic thin film of face centered cubic (FCC) lattice with Heisenberg spin-S are examined using the high-temperature series expansions technique extrapolated with Padé approximations method. The critical reduced temperature of the system τc is studied as function of thickness of the film and the exchange interactions in the bulk, and within the surfaces Jb, Js and J⊥ respectively. A critical value of surface exchange interaction above which surface magnetism appears is obtained. The dependence of the reduced critical temperature on the film thickness L has been investigated.