Low-energy electron-diffraction crystallographic determination for the Cu(110)2×1-O surface structure

Abstract

A multiple-scattering analysis of low-energy electron-diffraction intensities has been made for the Cu(110)2×1-O surface structure, a system for which different techniques have recently been providing very different conclusions regarding both the nature of the reconstruction of the copper structure and the height that the O atoms are held above (or below) the topmost Cu layer. The analysis here used nine diffracted beams at normal incidence, and it confirms the missing-row model for this surface. We find that the O atoms are held around 0.04 Å above the Cu atoms, while the first-to-second and second-to-third Cu-Cu interlayer spacings are expanded by 16% and contracted by 5% respectively from the bulk value. There is a vertical buckling in the third Cu layer by about 0.07 Å, and a possibly slight lateral relaxation (magnitude 0.03 Å) in the second copper layer.