Magnetic linear X-ray dichroism as a probe of the magnetocrystalline anisotropy

We show that for itinerant 3d transition metal systems the magnetocrystalli ne anisotropy energy is directly related to the anisotropic part of the spi n-orbit interaction, rather than to the orbital part of the magnetic moment as was previously suggested. We further show how the spin-orbit anisotropy can be obtained by applying the sum rule for magnetic linear dichroism in x-ray absorption. This provides an element specific tool to study metallic multilayer systems displaying novel magnetic properties, such as perpendicu lar magnetic anisotropy. [S0031-9007(98)08258-1].