▎ 摘　　要

Molecular dynamics simulation was performed to study the deformation behaviors of Zigzag Graphene Nano-Ribbons (ZGNRs) 150 angstrom x 150 angstrom in size, and double-elastic deformation was observed at temperatures lower than 90 K. Essentially, at such a low temperature, the lattice vibration was significantly weakened and thus the lifetime of C-C bonds was prolonged considerably. Moreover, it was difficult for broken bonds to accumulate and resulted in the destructive fracture of ZGNRs at low temperature. As a result, the "phase transformation" from hexagonal to quasi-rectangular and subsequently the second elastic deformation took place. However, at higher temperatures, says, 300 K, brittle fracture was observed and the fracture strength decreased with temperature, which was consistent with previously reported results. Additionally at higher strain rate, the atoms could not respond to the external loading in time, the fracture strain and fracture strength were enhanced. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.