Ab initiostudy of edge smoothing, atom attraction, and downward funneling in Ag/Ag(100)

Abstract

The results of density-functional theory (DFT) calculations of the energy barriers for three low-barrier relaxation processes in Ag/Ag(100) growth---edge-zipping, atom attraction, and downward funneling---are presented and compared with embedded atom method (EAM) calculations. In general, we find good agreement between the DFT values for these processes and the values assumed in recent simulations of low-temperature Ag/Ag(100) growth [Shim and Amar, Phys. Rev. B 81, 045416 (2010)]. We also find reasonable agreement between our DFT results and the results of EAM calculations, although in a few specific cases there is a noticeable disagreement. In order to investigate the effects of long-range interactions, we have also carried out additional calculations for more complex configurations. While our EAM results indicate that long-range interactions such as ``pinning'' can significantly enhance the energy barriers for edge-zipping and atom attraction, these effects can be significantly weaker in our DFT calculations due to the redistribution of the electron density.