O(2 x 1)-Ag(110) missing-row reconstruction: Structure determination by low-energy ion scattering.

Abstract

Impact collision ion scattering spectroscopy using ${\mathrm{Ne}}^{+}$ has been employed to determine the structure of the O(2\ifmmode\times\else\texttimes\fi{}1)-Ag(110) phase. The analysis of experimental data by Monte Carlo simulation of the ion trajectories confirms the missing-row reconstruction with the formation of -Ag-O-Ag- chains (added rows) along the 〈001〉 direction. Oxygen is found to occupy the long-bridge site 0.03\ifmmode\pm\else\textpm\fi{}0.08 \AA{} below the silver atoms, while the first-to-second and the second-to-third interlayer spacings are 1.66\ifmmode\pm\else\textpm\fi{}0.03 \AA{} and 1.32\ifmmode\pm\else\textpm\fi{}0.03 \AA{}, respectively. A lateral displacement (0.08\ifmmode\pm\else\textpm\fi{}0.03 \AA{}) of the second-layer Ag atoms towards the missing rows is observed in addition to a vertical buckling in the third layer: the atoms lying under the missing rows are held about 0.08 \AA{} above those positioned under the added rows.