New 2D Structures: Graphynes Under Tension

• Published in: Mechanics of solids 2024, Vol.59 (1), p.401-409
• Main Authors: Akhunova, A. Kh, Galiakhmetova, L. Kh, Baimova, J. A.
• Format: Article
• Language: English
• Subjects: Bonding strength; Carbon; Chemical bonds; Classical Mechanics; Crystal lattices; Deformation; Deformation mechanisms; Elongated structure; Flattening; Graphene; Mechanical properties; Molecular dynamics; Nanostructure; Physical properties; Physics; Physics and Astronomy; Tensile deformation; Ultimate tensile strength; Wrinkling
• ISSN: 0025-6544; 1934-7936
• DOI: 10.1134/S0025654424602726

The search for new materials for electronic or nanomechanical devices is of great importance today. Such 2D nanostructures as graphene have attracted much attention due to their unique physical and mechanical properties. Graphynes are a class of new nanostructures with sp- and sp2-hybridized carbon atoms arranged in a crystal lattice, which exhibit high strength and attractive electronic properties. In the present work, molecular dynamics is used to study the mechanical behavior of graphynes under tension at 0 K. Graphene, four graphynes β 1 -, β 3 -, γ 1 -, γ 2 - graphynes, and γ 1 ‑graphdiyne were considered. Tensile deformation is applied in such a way to allow wrinkling of the 2D structure. Two deformation mechanisms were found for all the considered structures: bond elongation and rotation combined with wrinkling/flattening of the 2D structure. It was found, that the higher the density of the structure, the higher the ultimate tensile strength under tension. Initially, weaker bonds between carbon atoms contributed to the tensile deformation, while at high strain, acetylenic bonds began to contribute. Changes in the valent angles also contribute significantly to the tensile behavior at different deformation stages, becoming critical at the final deformation stage. Tensile deformation is accompanied by the continuous wrinkling and then flattening of the 2D structure. Understanding the deformation behavior of such a novel structures as graphynes is of great importance for their future application in new electronic devices.