Elastic origin of the O/Cu(1 1 0) self-ordering evidenced by GIXD

We have studied by grazing incidence X-ray diffraction the self-ordering of the Cu–CuO stripe pattern. By comparing the experimental results to molecular dynamics simulations and anisotropic linear elastic calculations, we have been able to determine the atomic relaxations within the Cu substrate. The results show the importance of the crystalline anisotropy in the relaxation field. These relaxations are due to the surface stress difference Δσ between oxygen-covered and bare Cu(1 1 0) regions. For the different oxygen coverages studied, we have always found Δσ=1.0±0.1 N m−1. This surface stress difference is shown to be the origin of the self-ordering.