| With molecular dynamics simulations, deformation and fracture processes in ultranarrow graphene nanoribbons are examined. It is revealed that twisted and flat graphene nanoribbons having width of 4 atomic chains exhibit giant plasticity specified by plastic strain degrees of ≈180% and ≈290%, respectively. Such extremely high strain values were never observed in previous experiments and simulations. Plastic deformation of the graphene nanoribbons occurs through generation and re-arrangement of disclinations (non-six membered rings of carbon atoms) as well as transformations of disclinated graphene regions into monatomic carbon chains. Complete failure of the ultranarrow graphene nanoribbons is realized through breaks of C-C interatomic bonds at monatomic carbon chains characterized by high tensile strength of ≈45-50 GPa. |
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