Circular magnetic x-ray dichroism at the erbiumL3edge

The spin-dependent absorption of circularly polarized x rays at the ${\mathit{L}}_3$ edge of Er has been studied in ${\mathrm{Er}}_2$ ${\mathrm{Fe}}_{14}$B. Two distinct contributions, above and below the Fermi energy, are present. While they have been ascribed to dipolar and quadrupolar transitions to the empty 5d and 4f states, respectively, we find that the angular dependence of both features was well described as dipolar. The results are compared to a theoretical spectrum for Er metal.