Magnetic Circular Dichroism of Resonant X-Ray Emission Spectroscopy in Longitudinal and Transverse Geometries

抄録

Theoretical calculations and experimental measurements are performed for magnetic circular dichroism in resonant X-ray emission spectroscopy (MCD-RXES) in Gd³⁺ systems. It is shown that when the incident X-ray direction is perpendicular to the magnetization of the sample the MCD-RXES originates from the quantum mechanical interference which is characteristic of the coherent second order optical process, while when it is parallel to the magnetization the second order optical process reduces to the so-called two-step process with vanishing interference effect. The behavior of MCD-RXES calculated for the 2p → 5d electric dipole excitation and 3d → 2p dipole radiative decay in Gd³⁺ is in good agreement with that measured experimentally for a Gd₃₃Co₆₇ amorphous alloy. The effects of the 2p → 4f electric quadrupole excitation and the 2p → ε d electric dipole excitation are also studied.