The linearly polarized x-ray-absorption dichroism at the Dy 3d-4f edge is studied for three different kinds of interfaces: Dy on disordered Si(111), Dy on amorphous ${\mathrm{SiO}}_2$, and Dy on polycrystalline Ta. Strong dichroism is observed in all the three interfaces, despite the very different interactions of Dy with the substrates. It is therefore pointed out that the x-ray-absorption dichroism using linearly polarized light is a more widespread, but at the same time complicated, phenomenon than previously suspected.

• Received 28 March 1994

DOI:https://doi.org/10.1103/PhysRevB.50.8047