X-ray magnetic circular dichroism spectroscopy of transition metal thin films

Abstract A review is given of the principles underlying X-ray magnetic circular dichroism (XMCD) spectroscopy. The main strengths of the technique are highlighted. They are the quantitative determination of spin and orbital magnetic moments and their anisotropies through sum rule analysis of experimental spectra. A discussion is given why and how the spin and orbital magnetic moments in transition metal thin films are modified relative to the bulk. Selected XMCD results for thin films are discussed. “Non-magnetic” spacer layers sandwiched between magnetic layers are shown to become magnetic. The orbital moment is shown to become anisotropic in thin films, revealing that it is the microscopic origin of the magnetocrystalline anisotropy.

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