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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Anisotropic elastic modulus, high Poisson's ratio and negative thermal expansion of graphynes and graphdiynes

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Hernandez, Sergio A. ; Fonseca, Alexandre F.
Total Authors: 2
Document type: Journal article
Source: DIAMOND AND RELATED MATERIALS; v. 77, p. 57-64, AUG 2017.
Web of Science Citations: 9

Graphyne (GY) and graphdiyne (GDY) are two-dimensional one-atom-thick carbon allotropes highly considered to substitute graphene in electronic applications because of the prediction of non-null band-gap. There are multiple configurations of GY structures not yet fully investigated in literature. In this work, by means of classical molecular dynamics simulations, the Young's modulus, Poisson's ratio and linear thermal expansion coefficient (TEC) of all originally proposed seven types of GYs and corresponding GDYs are calculated. The dependence of these properties with the density of the structure is investigated for the first time. Quadratic increasing of the TEC of GY and GDY structures with density was found. The elastic modulus of GYs and GDYs were shown to be more sensitive to their density than general porous materials. In particular, non-symmetric structures are much softer along the armchair direction than along zigzag direction, implying that the elasticity along armchair direction of GY and GDY structures are similar to that of porous gels materials. Values larger than unity were found for the Poisson's ratio of some non-symmetric GYs and GDYs. A simple honeycomb mechanical model is shown to capture the observed values of Poisson's ratio of GYs and GDYs. (AU)

FAPESP's process: 16/00023-9 - Modeling and Simulation of Nanostructures and Nanostructured Materials
Grantee:Alexandre Fontes da Fonseca
Support type: Regular Research Grants