title: New structure model for the GaAs(001)-c(4x4) surface.
abstract: The surface structure of the As-stabilized GaAs(001)-c(4 x 4) surface has been studied. We show that the seemingly established three As-dimer model is incompatible with experimental data and propose here a new structure model which has three Ga-As dimers per c(4 x 4) unit cell. This mixed dimer model, confirmed by the rocking-curve analysis of reflection high-energy electron diffraction and first-principles calculations, resolves disagreements in the interpretation of several previous experiments. A good agreement between the observed scanning tunneling microscopy image and the simulated one further confirms the newly proposed model.
authors.affiliation: National Institute for Materials Science (NIMS), Tsukuba 305-0047, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohtake
authors.forename: Jun
authors.initials: J
authors.lastname: Nakamura
authors.forename: Shiro
authors.initials: S
authors.lastname: Tsukamoto
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Koguchi
authors.forename: Akiko
authors.initials: A
authors.lastname: Natori