Diffuse interface and strain anisotropy in Co/Pd(111) multilayers by polarized EXAFS study

Abstract

We examined interface structure of Co/Pd multilayers by quantitative analysis of fluorescence-yield Co K-edge EXAFS. To investigate the local atomic structure surrounding Co absorber and its anisotropy in orthogonal directions, two polarization dependent set-ups were used. By means of first shell analysis including distinct nearest neighbors of Co and Pd atoms, it was found that a considerable amount of Co-Pd alloy-like phase near interfaces of thin Co layers is formed by atomic scaled diffuseness of growing surface. Moreover, we found Co strain anisotropy depending on Co layer thickness, generally, tensile and compressive strains of in-plane and out-of-plane atoms, respectively. These interface structures might critically affect the tendency of perpendicular magnetization in Co/Pd multilayers.