عنوان مجله
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DIAMOND AND RELATED MATERIALS
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چکیده
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Classical molecular dynamics simulations have been performed to investigate five mechanical properties of
defective penta-graphene under uniaxial tension, namely Young's modulus, Poisson's ratio, ultimate tensile
stress, ultimate strain, and toughness. The reliable Erhart-Albe formulation of the Tersoff potential has been used
in the simulations and monovacancies are the only kind of structural defect studied. The effects of defect density,
chirality, and temperature on the mechanical properties are reported and thoroughly discussed. The results show
that by incorporating defects up to 20%, Young's modulus is decreased by more than one order of magnitude and
the sign of the mean Poisson's ratio changes to positive, which indicates the possibility of tuning this ratio.
Furthermore, the anisotropic behavior of the material is not strong in terms of Young's modulus, ultimate stress,
and ultimate strain and at higher temperatures, the ultimate stress, ultimate strain, and toughness almost
converge for pristine and defective penta-graphene. It can be concluded that PG is an auxetic material while it
can be tuned by defect engineering to behave as classic material. It should be noted that the results of current
study can be used as benchmark for design and fabrication of novel potential industrial materials with both
negative and positive Poisson's ratios.
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