• Detection of neutral atoms sputtered from ion‐bombarded single‐crystal surfaces Rh{111} and p(2×2) O/Rh{111}: Ejection mechanism and surface structure determinations from energy‐ and angle‐resolved measurements

A temporally sensitive ionization scheme is used in conjunction with a position‐sensitive detector to measure simultaneously energy‐ and angle‐resolved distributions of sputtered neutral atoms. We report results for 5‐keVAr⁺ ion‐bombarded Rh{111} single‐crystal surfaces, both clean and with a p(2×2) overlayer of oxygen atoms. The angular distributions and their variation with ejection kinetic energy are shown to give information about simple collision sequences that produce directionally preferential atom ejection. The changes that occur in the ejection distributions upon O atom adsorption suggest that O atoms occupy the ‘‘expected’’ sites, the sites that would be occupied by Rh atoms in a new monolayer.