First-principles calculation of the anomalous perpendicular anisotropy in a Co monolayer on Au(111)

We perform fully relativistic spin-polarized local spin density calculations for Au covered Co monolayer on Au(111). In accord with a trend observed in experiments we obtain an enhancement of perpendicular magnetic anisotropy as a function of the Au coverage. The close relationship found between the anisotropies of orbital magnetic moments and the anisotropy energies leads to an interpretation of our results in terms of familiar perturbation theory. By using this framework the anomalous behavior of the magnetic anisotropy energies can be well explained due to changes in the sp-d hybridization at the interface of Co monolayer and Au cap.