Defect formation and transformation in graphene under electron irradiation: A molecular dynamics study

Molecular dynamics simulations were performed to study defect formation and transformation in graphene under electron irradiation. The single-vacancy was the most frequently formed defect and the number of defects did not depend on the defect formation energy for normal incidence. The single-vacancy transformed to other types of defects and migrated in graphene by heating. The recovery energies of adatom-vacancy and pentagon-heptagon defects were relatively small. The Stone-Wales defect was the most stable, and did not easily recover. In the single atomic chain formation process from graphene by electron irradiation, competition between defect formation by electron collision and the recovery by heating was observed. (C) 2014 American Vacuum Society.