Surfactants used in Ag(111) homoepitaxy: Sb, In, Pt and O2

We have investigated the effect of several surfactants on the homoepitaxial growth of Ag(111) by X-ray reflectivity experiments. Recently, we found that submonolayer amounts of Sb induce layer-by-layer growth of Ag on Ag(111). Now we have varied the amount of Sb and also used In, Pt and O₂ as surfactant. We show that Sb is not unique in inducing two-dimensional growth in Ag(111) homoepitaxy: In and Pt have the same effect. For O₂ the sticking coefficient to Ag(111) is too low to affect the growth significantly. At the lowest growth temperatures (< 170 K), only Sb induces layer-by-layer growth.