Magnetic circular dichroism of the x-ray-emission spectra for the 2p→1s decay in Co metal

The magnetic circular dichroism (MCD) of x-ray emission spectroscopy (XES) was measured at Co Kα_1,2 (2p → 1s decay) in Co metal with the energies of the incident x rays chosen to be 7713 eV, 7720 eV, and 7730 eV around the Co K edge (7708 eV), respectively. The maximum amplitude of the MCD was about 0.25%, as was normalized by the peak heights of the Kα₁ diagram line, and was on the same order as the MCD of the x-ray absorption spectra at the Co K edge. The MCDXES, which is quite weak due to the absence of a spin-orbit interaction in the 1 s state, originated from a weak spin-orbit interaction of the 4p state. The shapes of the observed MCD-XES were full of varieties depending on energies of incident x rays, where it was considered that they depended mainly on the multiplet effects as 2p-3d exchange interaction at the final state.