2007/08/18 by Bo Sun, Ping Zhang, Zhigang Wang +6
Materials Science · Physics and Astronomy · #Catalytic Processes in Materials Science #Electronic and Structural Properties of Oxides #Surface and Thin Film Phenomena #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevb.78.035421
31 pages, 16 figures
arxiv created 2007/08/18 · openalex publication_date 2008/07/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the atomic oxygen adsorption on Pb(111) surface by using density-functional theory within the generalized gradient approximation and a supercell approach. The atomic and energetic properties of purely on-surface and subsurface oxygen structures at the Pb(111) surface are systematically investigated for a wide range of coverage and adsorption sites. The fcc and tetra-II sites (see the text for definition) are found to be energetically preferred for the on-surface and subsurface adsorption, respectively, in the whole range of coverage considered. The on-surface and subsurface oxygen binding energies monotonically increase with the coverage, and the latter is always higher than the former, thus indicating a tendency to the formation of oxygen islands (clusters) and the higher stability of subsurface adsorption. The on-surface and subsurface diffusion-path energetics of atomic oxygen, as well as the activation barriers for oxygen penetration from the on-surface to the subsurface sites, are presented at low and high coverage. The other properties of the O/Pb(111) system, including the charge distribution, the lattice relaxation, the work function, and the electronic density of states, are also studied and discussed in detail. It is pointed out that the O-Pb chemical bonding during surface oxidation displays a mixed ionic/covalent character. Here the ionicity is featured by a charge flow from Pb 6p to O 2p states, while the covalency is featured by the Pb 6s2 ``lone pair'' effect, which results from hybridization of Pb 6s and O 2p states.