Abstract:
The properties of hexagonal graphene are modeled by the ab initio pseudopotential method within the density functional theory taking into account the effect of the vacancies associated with the short-range order structure. The magnetic properties of graphene supercells with 18, 54, and 96 carbon atoms with mono and divacancies are calculated. The introduction of carbon vacancies onto the graphene monolayer induces the appearance of a local magnetic moment. The numerical estimates of the value of the magnetic moment are executed for graphene supercells with 18, 54, and 96 carbon atoms with vacancies. The values of the magnetic moments are obtained, and the region of localization of spin density in the supercell with 96 carbon atoms which includes both short-range and long-range vacancies is determined. The effect of the distance between the vacancies on the value of the magnetic moment in a graphene supercell is studied. The dependences of the magnetic moment and distance between the vacancies in a graphene supercell with 96 atoms on the concentration of the vacancies are investigated. Using the calculations of the energy of formation of carbon vacancies in a graphene supercell, its dependences on the deformation of the graphene cell are studied
Keywords:ab initio calculation, density functional theory, graphene supercells, vacancies, magnetic moment, spin density, position of vacancies, energy of formation and concentration of vacancies, deformation of a graphene cell.
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