Resonant magneto-optical properties of disordered Fe0.5Ni0.5 and CoxPt1−x alloys in the X-ray regime

An application of the relativistic version of the Kubo-formula for the optical conductivity to investigate the resonant magneto-optical properties of disordered alloys in the X-ray regime is presented. Results obtained for the magnetic dichroic part of the complex refractive index n at the L2,3-edges of Fe and Ni in fcc-Fe0.5Ni0.5 are found in very good agreement with recent experimental findings. The relation of n with the local magnetic moment is discussed on the basis of results obtained for the L2,3-edges Pt in fcc-CoxPt1−x.