title: Structure of a CH3S monolayer on Au(111) solved by the interplay between molecular dynamics calculations and diffraction measurements.
abstract: We have investigated the controversy surrounding the (sqrt[3] x sqrt[3]) R30 degrees structure of self-assembled monolayers of methylthiolate on Au(111) by first principles molecular dynamics simulations, energy and angle resolved photoelectron diffraction, and grazing incidence x-ray diffraction. Our simulations find a dynamic equilibrium between bridge site adsorption and a novel structure where 2 CH3S radicals are bound to an Au adatom that has been lifted from the gold substrate. As a result, the interface is characterized by a large atomic roughness with both adatoms and vacancies. This result is confirmed by extensive photoelectron and grazing incidence x-ray diffraction measurements.
authors.affiliation: International School for Advanced Studies, Trieste, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Mazzarello
authors.forename: A
authors.initials: A
authors.lastname: Cossaro
authors.forename: A
authors.initials: A
authors.lastname: Verdini
authors.forename: R
authors.initials: R
authors.lastname: Rousseau
authors.forename: L
authors.initials: L
authors.lastname: Casalis
authors.forename: M F
authors.initials: MF
authors.lastname: Danisman
authors.forename: L
authors.initials: L
authors.lastname: Floreano
authors.forename: S
authors.initials: S
authors.lastname: Scandolo
authors.forename: A
authors.initials: A
authors.lastname: Morgante
authors.forename: G
authors.initials: G
authors.lastname: Scoles