Faceting Induced by Ultrathin Metal Films: A First Principles Study

Abstract

Using first principles calculations, we studied the overlayer growth mode and the substrate stability when ultrathin layers of various metals are grown on a Mo(111) substrate. We found that the growth mode is Stranski-Krastanov, and the overlayer can induce the substrate to facet, in accordance with recent experimental observations. The growth-induced instability of the substrate towards faceting is driven by the enhancement of the surface energy anisotropy. However, faceting can be forbidden in some cases if the overlayer adsorption does not lower the surface formation energy significantly.