An experimental and theoretical investigation of the structural and micromagnetic properties of the ${\mathrm{Co}}_{50}{\mathrm{Pt}}_{50}$ ordered alloy is presented. The Co-$3d$ and Pt-$5d$ orbital and spin magnetic moments and their anisotropies are determined by means of angle-dependent x-ray magnetic-circular-dichroism (XMCD) measurements. Our calculated spin magnetic moments of both Co and Pt are in good agreement with our experimental results, while the orbital magnetic moments are underestimated. The reduction of the $3d$ and $5d$ orbital magnetic moments, observed when the spin magnetic moment is forced out of the easy axis of magnetization, is reproduced by the theory. The calculated XMCD reproduces semiquantitatively the experimental spectra and underestimates the so-called branching ratio. The computed magnetocrystalline anisotropy is of the same order of magnitude as the experimental one with the correct sign.

• Received 13 January 1999

DOI:https://doi.org/10.1103/PhysRevB.62.1157