Magnetic anisotropy in Fe/Cu(001) overlayers and interlayers: The high-moment ferromagnetic phase

An extensive study of the magnetic anisotropy energies (MAE's) of the high-moment ferromagnetic phase of fee Fe/Cu(001) overlayers and interlayers is presented in terms of the fully relativistic spin-polarized screened Korringa-Kohn-Rostoker method. Independent of the film thickness for free surfaces the orientation of the magnetization is found to be in-plane, while for capped films a perpendicular magnetization is predicted up to a switching thickness of five Fe monolayers, Based on an analysis of layer-resolved anisotropy energies it is shown that the main contribution to the MAE's arises from the Fe layer at the Fe/Cu interfaces. Particular features of the MAE's with respect to the number of cap layers as well as to the film thickness can be viewed in terms of an interfacial hybridization between Fe and Cu. By using the coherent-potential approximation the interdiffusion between the substrate and the magnetic film is shown to reduce the MAE dramatically.