Orientation Dependence of γ-Graphyne Strength: Molecular Dynamics

Graphynes are two-dimensional materials composed of sp- and sp2-hybridized carbon atoms. They are promising materials for future electronic devices due to their unique electronic and optical properties. In the present work, the orientation dependence of γ1-graphyne strength and fracture strain with the detailed analysis of the deformation behavior is carried out by molecular dynamics. Graphynes with different chirality from 0° (armchair) to 30° (zigzag) are considered. It is found that γ1-graphyne strength depends on chirality: the highest strength (42.7 N/m) is found for zigzag direction. The Young’s modulus and fracture strain does not depend on the γ1-graphyne chirality. The main deformation mechanisms are revealed: elongation of covalent bonds and rotation of valence angles. The obtained results allow a better understanding of the effect of the γ1-graphyne chirality on their mechanical properties for future applications.