Structure of a CH3S monolayer on Au(111) solved by the interplay between molecular dynamics calculations and diffraction measurements

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Mazzarello R., Cossaro A., Verdini A., Rousseau R., Casalis L., Danisman M. F., ...More

PHYSICAL REVIEW LETTERS, vol.98, no.1, 2007 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 98 Issue: 1
  • Publication Date: 2007
  • Doi Number: 10.1103/physrevlett.98.016102
  • Journal Name: PHYSICAL REVIEW LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes

Abstract

We have investigated the controversy surrounding the (root 3x root 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.