Patel, J. R.Golovchenko, JeneFreeland, P. E.Gossmann, H- J.2016-11-181987Patel, J. R., J. A. Golovchenko, P. E. Freeland, and H- J. Gossmann. 1987. Arsenic Atom Location on Passivated Silicon (111) Surfaces. Physical Review B 36, no. 14: 7715-7718. doi:10.1103/physrevb.36.7715.0163-1829http://nrs.harvard.edu/urn-3:HUL.InstRepos:29407038The position of As atoms on a clean Si(111) surface has been determined with x-ray standing waves in ultrahigh vacuum. The As atoms occupy exclusively the top half of the silicon (111) double plane and lie at 0.17 Å above the unrelaxed bulk terminated silicon (111) plane. This value is in good agreement with recent total-energy minimization calculations. A significant but limited stability of As passivated surfaces is observed upon exposure to various ambients. We also present general arguments showing how surface specificity can be achieved with x-ray standing-wave measurements such as the above, where bulk-symmetry site-occupancy rules are broken.en-USJournal Article2016-11-1810.1103/PhysRevB.36.7715