Photoemission forward scattering from ErAs(100)/GaAs(100)

Epitaxial thin films of the rare earth pnictide ErAs(100), grown on GaAs(100), have been characterized by angle-resolved X-ray photoelectron studies. Forward scattering effects are observed due to the excellent stoichiometry of the ErAs film from the surface to the bulk. The increasing in the Ga core level intensity, leading to a drop in the Er/Ga core level intensity ratio along the 〈103〉 and 〈101〉 directions, indicates that there is in-plane registry of the ErAs overlayer film with the GaAs substrate at the thin film interface.