Threshold displacement energies in graphene and single-walled carbon nanotubes

Article

关键词: MOLECULAR-DYNAMICS;    ELECTRON;    STABILITY;   

DOI  :  10.1103/PhysRevB.92.075404

来源: SCIE

【 摘 要 】

The threshold displacement energy E-d has been determined for graphene and 216 different (n, m) single-walled carbon nanotube chiralities, with 5 <= n <= 20 and 0 <= m <= n, under several model conditions using classical molecular dynamics. The model conditions vary by particle (electron or carbon ion), empirical potential (two parametrizations of Tersoff [J. Tersoff, Phys. Rev. B 39, 5566 (1989); L. Lindsay and D. A. Broido, 81, 205441 (2010)] and one of Brenner et al. [D. W. Brenner, O. A. Shenderova, J. A. Harrison, S. J. Stuart, B. Ni, and S. B. Sinnott, J. Phys.: Condens. Matter 14, 783 (2002)]), and momentum transfer direction (towards or away from the nanotube axis). For electron irradiation simulations, E-d exhibits a smoothly varying chirality dependence and a characteristic curvature influenced by the momentum transfer direction. Changing the empirical potential shifts the magnitude of E-d, but the trend is preserved for electron simulations. However, the perturbation in the knock-on dynamics introduced by the carbon ion leads to E-d trends that diverge from the equivalent electron simulation. Thus, the ion interaction has a non-negligible effect on the dynamics of the collision and leads to E-d values that can distinctly vary depending on the selected carbon nanostructure.

【 授权许可】

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