Abstract
Motivated by our recent scanning tunneling microscopy measurements on that, depending on the nature of the adsorbate, showed the formation of distinct facets when the substrate is annealed to elevated temperatures, we used density-functional theory to explore why faceting of induced by is different from that by . Our calculations indicate that nitrogen adsorption causes two-sided ridges, combining and faces, to become thermodynamically favored at temperatures below 1080 K while oxygen adsorption below 1130 K leads to four-sided pyramids exhibiting , , , and faces.
- Received 27 March 2009
DOI:https://doi.org/10.1103/PhysRevB.79.132107
©2009 American Physical Society