Effect of Co seed layers on the magnetic anisotropy of Au/Co metallic multilayers

Au/Co(111) multilayers and a Au buffer layer were grown by MBE on Al₂O₃(0001) substrates using a thin Co seed layer. The influence of the Co layer on the structure of the Au/Co multilayers was studied by X-ray diffraction and reflection high-energy electron diffraction (RHEED), and compared to its effect on the magnetic anisotropy. The Au buffer layer grown on Al₂O₃(0001) substrates display a large fraction of (111) fiber texture, giving rise to a lack of lateral continuity in the film. The initial deposition of a few monolayers of Co onto Al₂O₃(0001) substrates prior to deposition of the Au buffer layer yielded (111) epitaxial films with no texture. The use of this seeded epitaxy results in a highly improved structural quality of Au/Co(111) multilayers. From the results of Low-angle X-ray diffraction and RHEED observations, we confirmed that the interfaces of Au/Co multilayers with Co seed layer are sharper than those without Co seed layer. It cleary shows that the use of Co seed layer improved the periodicity of Au/Co multilayers. The magnetic anisotropy energy of Au/Co multilayers increased by using the Co seed layer, and the high quality of structure results larger perpendicular magnetic anisotropy.