Strong dichroism in the Dy 3<i>d</i>→4<i>f</i>x-ray absorption at Dy/Si(111) interfaces

Abstract

We report experimental evidence for strong 3d\ensuremath{\rightarrow}4f x-ray-absorption dichroism in rare-earth ions on a nonmagnetic substrate: Dy on Si(111)7\ifmmode\times\else\texttimes\fi{}7. The results are discussed by evaluating the role of the crystal-field splitting of the ground state as an alternative to the Zeeman splitting underlying the magnetic x-ray dichroism theory.