Structural details for the Cu(110)-c(6 × 2)-O surface determined by tensor LEED

Abstract

A tensor LEED analysis has been made for the Cu(110)-c(6 × 2)-O surface structure using intensity versus energy curves measured for 13 diffracted beams at normal incidence. A good level of correspondence between experimental and calculated intensities has been reached ( R p = 0.271) for the model type ( 2 3 monolayer coverage of O) proposed for this surface by Feidenhans'l et al. This analysis provides direct information on the structural details, and it is indicated that they support the view that the driving force for this structure relates to sufficient O being incorporated in order to stabilize the surface as a modified (211) plane of bulk Cu 2O. This structure is composed of double-stranded chains built from 12-membered rings formed by alternating O and Cu atoms. The chains are flattened on the surface, and alternating chains are laterally displaced by half a repeat unit compared with the bulk (211) plane. However, the three-atom OCuO fragments essentially maintain their bulk form in the surface structure. The average OCu bond length in Cu(110)-c(6 × 2)-O is indicated to equal 1.90 Å, in exact agreement with the values determined for the half monolayer structures formed by O on Cu(110) and Cu(100).