We study the bonding and diffusion of Au in graphene vacancies using density-functional theory. Energetics show that Au adsorbs preferably to double vacancies, steadily in-plane with graphene. All diffusion barriers for the complex of Au in double vacancy are above 4 eV, whereas the barriers for larger vacancies are below 2 eV. Our results support the main results of a recent experiment [Gan et al., Small 4, 587 (2008)], but suggest that the observed diffusion mechanism is not thermally activated, but radiation-enhanced.
@article{arxiv.0812.3751,
title = {Gold in graphene: in-plane adsorption and diffusion},
author = {S. Malola and H. Häkkinen and P. Koskinen},
journal= {arXiv preprint arXiv:0812.3751},
year = {2009}
}