Dependence of the Curie temperature on the thickness of an ultrathin film

The effect the thickness of an ultrathin film has on magnetic ordering is analyzed using the Ising model. It is shown that the dependence of the relative change in the Curie temperature on the thickness of an ultrathin film obeys a power law with an exponent equal to reverse critical exponent of spin-spin correlations ν = 0.69. The obtained results are in good agreement with the experimental data.