X-ray analysis of oxygen-induced perpendicular magnetic anisotropy in Pt/Co/AlOx trilayers

X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlO(x) trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy of the Co/AlO(x) interface. It is observed that high temperature annealing modifies the magnetic properties of the Co layer, inducing an enhancement of the perpendicular magnetic anisotropy. The microscopic structural properties are analyzed via X-ray Absorption Spectroscopy, X-ray Magnetic Circular Dichroism and X-ray Photoelectron Spectroscopy measurements. It is shown that annealing enhances the amount of interfacial oxide, which may be at the origin of a strong perpendicular magnetic anisotropy. (C) 2008 Elsevier B. V. All rights reserved.