Experimental and theoretical x-ray magnetic-circular-dichroism study of the magnetic properties of Co50Pt50 thin films

An experimental and theoretical investigation of the structural and microma gnetic properties of the Co,,Pt,, ordered alloy is presented. The Co-3d and Pt-Sd orbital and spin magnetic moments and their anisotropies are determi ned by means of angle-dependent x-ray magnetic-circular-dichroism (XMCD) me asurements. Our calculated spin magnetic moments of both Co and Pt are in g ood agreement with our experimental results, while the orbital magnetic mom ents are underestimated. The reduction of the 3d and 5d orbital magnetic mo ments, observed when the spin magnetic moment is forced out of the easy axi s of magnetization, is reproduced by the theory. The calculated XMCD reprod uces semiquantitatively the experimental spectra and underestimates the so- called branching ratio. The computed magnetocrystalline anisotropy is of th e same order of magnitude as the experimental one with the correct sign.