FACETING INDUCED BY ULTRATHIN METAL-FILMS - A FIRST PRINCIPLES STUDY

Using first principles calculations, we studied the overlayer growth m ode and the substrate stability when ultrathin layers of various metal s are grown on a Mo(111) substrate. We found that the growth mode is S transki-Krastanov, and the overlayer can induce the substrate to facet , in accordance with recent experimental observations. The growth-indu ced instability of the substrate towards faceting is driven by the enh ancement of the surface energy anisotropy. However, faceting can be fo rbidden in some cases if the overlayer adsorption does not lower the s urface formation energy significantly.