Chemical order and magnetic anisotropy in alternate Fe/Co monolayers on Cu₃Au(001)

In this work, we have investigated the magnetic anisotropy of Fe/Co layers epitaxially grown on Cu3Au(001). The ordered Fe/Co thin films were prepared by deposition of alternated monolayers of Fe and Co. The stoichiometry, structure, morphology and magnetic properties of the films were characterized in-situ using XPS, LEED, RHEED, STM and MOKE techniques respectively. Measuring the film properties after the deposition of each monoatomic layer, we have shown that the chemical order and the surface layer also play an important role in establishing the film magnetic anisotropy. Our results show that the effective magnetic anisotropy can be tuned from in-plane to out-of-plane depending on which material (Fe or Co) the alternated film is terminated. These results were compared to codeposited films that presented in-plane magnetic anisotropy for all film thicknesses. In addition, the spin and orbital magnetic moments of Fe and Co atoms in a 6 ML film were extracted applying XMCD sum rules.