X-ray magnetic circular dichroism spectroscopy of transition metal multilayers

Over the last few years the X-ray magnetic circular dichroism (XMCD) technique has evolved into an important magnetometry tool and the present article describes the principles and unique strengths of the technique. They are the quantitative determination of element-specific spin and orbital magnetic moments and their anisotropies through sum rule analysis of experimental spectra. In particular, we discuss applications of the XMCD technique to the study of transition metal multilayers. We show that a thin film of a non-magnetic metal like Cu may become magnetically alive and a thin film of a ferromagnetic metal like Fe may become magnetically dead. The anisotropy of the orbital magnetic moment is shown to be the microscopic origin of the magnetocrystalline anisotropy.