Magnetic anisotropic properties of Pd/Co/Pd trilayer films studied by X-ray absorption spectroscopy and magnetic circular dichroism

Abstract

We study the magnetic anisotropic properties of as-grown and annealed Pd/Co/Pd trilayer films based on their atomic and electronic structures using extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES) spectroscopy and magnetic circular dichroism (XMCD) measurements. The annealed film exhibits interesting perpendicular magnetic anisotropy (PMA) whereas the as-grown film exhibits in-plane anisotropy. Cross-sectional transmission electron microscopic analysis together with the Co K-edge EXAFS results confirm the formation of an ordered-alloy CoPd phase in the annealed film, whereas the as-grown film has an hcp Co-like phase. Co L_3,2-edge XMCD measurements reveal an enhanced ratio of the Co 3d orbital to spin moments of the annealed film providing evidence of the observed PMA upon annealing.