Dislocation dipole in graphene at finite temperatures

Abstract

Abstract In the present work, the evolution of defect structure of graphene with dislocation dipole of three types in thermal equilibrium is studied by molecular dynamics simulations. The presence of defects can considerably reduce the temperature at which graphene remains stable in thermal equilibrium. It is found, that at elevated temperatures, there is a movement of dislocations in a dipole with arm equal to 7 Å, so that a new dipole with the arm 3 Åis formed with the further transformation to the Stone-Wales defect. This reveals that dipole arm is less than annihilation distance for dislocation dipole. Again, the Stone–Wales defect at elevated temperatures disappears as a result of the rotation of the C–C bond. The obtained results will allow describing the dynamics of defects in graphene in thermal equilibrium, which can be helpful to analytically describe dislocation dynamics in graphene.