The experimentally determined thin-film limit to the Ginzburg-Landau model of thin-film magnetism

Experimental device is provided for terbium overlayers on Fe(100) demonstrating that the Ginzburg-Landau model fails for ferromagnetic terbium at submonolayer coverages. This failure of mean field theory to successfully describe experimental data occurs quite close to the site percolation limit of 0.5 to 0.59 monolayers, and the coverage at which appreciable second layer absorption occurs in a simultaneous multilayer growth model. For thicker films, modeling of the experimental data suggests that the thickness dependence of the magnetization depends very strongly upon temperature, as expected.