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Structure of a CH 3 S Monolayer on Au(111) Solved by the Interplay between Molecular Dynamics Calculations and Diffraction Measurements

2007; American Physical Society; Volume: 98; Issue: 1 Linguagem: Inglês

10.1103/physrevlett.98.016102

1092-0145

Riccardo Mazzarello, Albano Cossaro, Alberto Verdini, Roger Rousseau, Loredana Casalis, M. Fatih Danışman, Luca Floreano, Sandro Scandolo, A. Morgante, G. Scoles,

nanoparticles nucleation surface interactions

We have investigated the controversy surrounding the $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ 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 ${\mathrm{CH}}_{3}\mathrm{S}$ 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.