Photoelectron diffraction evidence for a surface substitutional site of Sb in the Sb-induced smooth growth of Ag on Ag(111)

We apply low-energy photoelectron diffraction to study the crystalline site of Sb, either adsorbed onto Ag(111) or segregated on its surface after silver homoepitaxy. The experimental data are interpreted in the framework of full multiple-scattering theory with complex potentials for different Sb positions. We conclude in favor of a surface substitution site for Sb, and we also draw some conclusions about the Sb-Sb environment. Our findings seem to corroborate the suggestion put forward by Vrijmoeth et al. [Phys. Rev. Lett. 72, 3843 (1994)] regarding the Sb-induced smooth growth of Ag on Ag(111).