Temperature dependence of the magnetization of transition-metal thin films: Fe- monolayers and bilayers

The functional integral theory of bulk itinerant magnetism is extended to be applied to low-dimensional transition-metal systems. Using a real-space recursive expansion of the local Green’s function we calculate the magnetization curves and the Curie temperature TC for the bulk, monolayer, and bilayer of Fe. Disorder is treated by using the virtual crystal approximation. The local-environment dependence of TC is analyzed by comparing the results for bulk and the (001) and (110) oriented films of Fe. Finally, the applicability of the theory is discussed.