Rare-earth contributions to the x-ray magnetic circular dichroism at the CoKedge in rare-earth–cobalt compounds investigated by multiple-scattering calculations

The x-ray magnetic circular dichroism (XMCD) has been measured at the Co K edge in hcp-Co and R-Co compounds $(R=\mathrm{L}\mathrm{a},\mathrm{T}\mathrm{b},\mathrm{D}\mathrm{y}).$ The structure of the experimental XMCD spectra in the near-edge region has been observed to be highly sensitive to the magnetic environment of the absorbing site. Calculations of the XMCD have been carried out at the Co K edge in Co metal, ${\mathrm{LaCo}}_{5},$ and ${\mathrm{TbCo}}_{5}$ within the multiple-scattering framework including the spin-orbit coupling. In the three systems, the XMCD spectra in the near-edge region are well reproduced. The possibility to separate the local effects from those due to the neighboring atoms in the XMCD cross section makes possible a more physical understanding of the spectra. The present results emphasize the major role played by the d states of the Tb ions in the XMCD spectrum at the Co K edge in the ${\mathrm{TbCo}}_{5}$ compound.