Adsorption and diffusion of SCH3 radicals and Au(SCH3)(2) complexes on the unreconstructed Au(111) surface in the submonolayer coverage regime

作者：Franke Andreas^*; Pehlke Eckhard

来源：Physical Review B, 2009, 79(23): 235441.

DOI：10.1103/PhysRevB.79.235441

We study the adsorption and diffusion of Au(SCH3)(2) complexes as well as bare SCH3 radicals on the unreconstructed Au(111) surface using density-functional theory. Maksymovych et al. observed these complexes at the Au(111) surface by scanning tunneling microscopy. In accordance with previous densityfunctional theory studies by other groups, we find a slight energetical preference for the bonding of SCH3 on the surface in Au(SCH3)(2) complexes. The net energy gain accounting for the creation of one Au adatom amounts to approximately 0.2 eV per SCH3 radical. The diffusive motion of these complexes includes rotational and translational diffusion steps with energy barriers of 0.44 eV and 0.37 eV, respectively. We speculate whether this may result in a correlation of the direction of consecutive diffusion events. In case of bare SCH3 radicals we calculate a diffusion barrier of 0.26 eV.

• 出版日期2009-6