Determining element-specific magnetocrystalline anisotropies using x-ray magnetic linear dichroism

X-ray magnetic linear dichroism (XMLD) is shown to be an element-specific probe of the magnetocrystalline anisotropy (MAE). The anisotropy in the spin-orbit interaction, determined using XMLD, is related to the MAE using a sum rule for a series of stepped Co surfaces exhibiting increasing uniaxial magnetic anisotropy. A linear relationship between the MAE, determined using XMLD, and the step density driven increase in the magnetic anisotropy proves the link between XMLD and the MAE. The element-specific nature of the technique is demonstrated by determining the individual MAE for Co/Fe bilayers.