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 (3×3)R30° 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.
- Publication:
-
Physical Review Letters
- Pub Date:
- January 2007
- DOI:
- 10.1103/PhysRevLett.98.016102
- Bibcode:
- 2007PhRvL..98a6102M
- Keywords:
-
- 68.43.Fg;
- 68.43.Bc;
- 68.49.Uv;
- 79.60.Dp;
- Adsorbate structure;
- Ab initio calculations of adsorbate structure and reactions;
- X-ray standing waves;
- Adsorbed layers and thin films