Density functional theory calculations of adsorption-induced surface stress changes

Density functional theory calculations of adsorbate-induced surface stress changes have been performed for a number of adsorbate and overlayer systems for which experimental data exists, namely: oxygen and sulphur adsorption on Ni(100); oxygen adsorption on W(110); pseudomorphic growth of Ni on Cu(100) and of Fe on W(110); oxygen adsorption on a 5 ML pseudomorphic film of Ni(100) grown on Cu(100). The theoretical calculations reproduce all the qualitative features of the experimental data, but there are some significant quantitative differences, most notably for the two atomic adsorbates on the bulk Ni(100) surface, for which the theoretical stress changes are substantially smaller than the experimental ones, a situation not obviously attributable to experimental error. For the W(110)/Fe system there is also a marked difference between experiment and theory in the coverage at which key surface stress changes occur. (c) 2007 Elsevier B.V. All rights reserved.