Using first-principles calculation, a study was made of adatom-vacancy pairs on graphenes. It was found that the healing barrier of the adatom-vacancy pair was very small (0.06eV) when the adatom was bonded to a nearest carbon atom of the mono-vacancy. Therefore, this pair was easily healed. On the contrary, when the adatom was located 4.26 to 5.54Å far from the vacant site, the healing barrier became high (0.24 to 0.32eV), but these barriers were lower than that of the adatom diffusion. It was therefore expected that these adatom-vacancy pairs were healed in low temperature range where the adatom did not diffuse.

First-Principles Calculations of Adatom-Vacancy Pairs on Graphene. Lin, J., Nishida, K., Saito, M.: Japanese Journal of Applied Physics, 2012, 51[12], 125101