A study was made of the bonding and diffusion of Au in graphene vacancies using density-functional theory. Energetics showed that Au adsorbs preferably to double vacancies, steadily in-plane with graphene. All diffusion barriers for the complex of Au in double vacancy were above 4eV, whereas the barriers for larger vacancies were below 2eV. The results supported the main results of experiment (Gan, 2008) but suggested that the observed diffusion mechanism was not thermally activated but radiation-enhanced.

Gold in Graphene: In-Plane Adsorption and Diffusion. Malola, S., Häkkinen, H., Koskinen, P.: Applied Physics Letters, 2009, 94[4], 043106