Simple lattice-dynamical slab model for interpreting surface vibrational spectra: Application to oxygen on Ni(100) and Ni(111)

Abstract

A parametrized lattice-dynamical slab model is presented and used to analyze the vibrational properties of oxygen adsorbed on Ni(100) and Ni(111) surfaces. Results obtained from the slab-model technique are compared with corresponding predictions based on a Greens's-function approach to contrast the relative merits of these two methods for obtaining information about vibrational phenomena. The lattice-dynamical slab model is also used to analyze experimental data for several ordered oxygen configurations on the Ni(111) and Ni(100) surfaces, including the proposed pseudobridge site for c(2\ifmmode\times\else\texttimes\fi{}2) oxygen on Ni(100). The results presented indicate that lattice-dynamical calculations can be used not only to test structural models proposed on the basis of experimental measurements or other theoretical calculations, but can also serve as a basis for independent structural determinations (bonding sites and bond lengths) when there is sufficient surface vibrational data to constrain the calculations adequately.