Scattering and recoiling imaging spectrometry (SARIS) study of chlorine chemisorption on Ni(110)

The clean and chlorine chemisorbed Ni(1 1 0) surface has been investigated by scattering and recoiling imaging spectrometry (SARIS). Rare gas ion beam s at 4 keV were scattered at different incident (alpha) and exit (beta) ang les along different azimuthal directions of the surface. The LEED pattern c hanged from a sharp (1 x 1) to a weak (3 x 1) after exposure to Cl-2. The H e+ images from the Cl/Ni surface exhibited very little differences compared to those of the clean surface. This is due to the high penetration depth o f the He+ ions, which results in low surface sensitivity. The images obtain ed from the Cl/Ni surface with the heavier ions exhibited obvious changes d ue to their low penetration depths, which facilitates high surface sensitiv ity. Scattering and Recoiling Imaging Code (SARIC) simulations were carried out in order to interpret the perturbations induced by the chlorine adatom s. Different chemisorption sites for chlorine were tested. The results of t he experiments and simulations agree that Cl atoms are chemisorbed in the s hort-bridge sites above the [<1(1)over bar>0] rows. (C) 1999 Elsevier Scien ce B.V. All rights reserved.