Low energy ion scattering study of oxygen adsorption on a Cu{100} single crystal surface : Part I : Surface characteristics

Abstract

The surface characteristics of the oxygen-covered Cu{100} surface have been studied using Low Energy Ion Scattering. The results indicate that already at the second adsorption stage (LEED: (√2 × √2)R45°-O structure) two essentially different oxygen positions are involved. There are some indications that in the third adsorption stage (LEED: (√2 × 2 √2)R45°-O structure) oxygen incorporation into the selvedge takes place. The structure in the azimuthal distributions of O− recoil ions is in accordance with two essentially different oxygen positions, possibly at the positions as proposed by Onuferko and Woodruff: in this model oxygen is initially adsorbed into 2-fold bridge sites 1.4 Å above the surface and subsequently incorporated into 4-fold sites in the first copper surface layer.

After oxygen exposures in the second stage a copper surface that is not reconstructed is observed.