The normal-auxeticity mechanical phase transition in graphene. (10th March 2017)

• Record Type: Journal Article
• Authors: Deng, Binghui; Hou, Jie; Zhu, Hanxing; Liu, Sheng; Liu, Emily; Shi, Yunfeng; Peng, Qing
• Is Part Of: 2D materials. Volume 4:Number 2(2017)
• Publication Date: 2017-03-10
• Subjects: graphene -- auxeticity -- mechanical phase transition -- Poisson's ratio; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aa61e5
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: When a solid object is stretched, in general, it shrinks transversely. However, the abnormal ones are auxetic, which exhibit lateral expansion, or negative Poisson ratio. While graphene is a paradigm 2D material, surprisingly, graphene converts from normal to auxetic at certain strains. Here, we show via molecular dynamics simulations that the normal-auxeticity mechanical phase transition only occurs in uniaxial tension along the armchair direction or the nearest neighbor direction. Such a characteristic persists at temperatures up to 2400 K. Besides monolayer, bilayer and multi-layer graphene also possess such a normal-auxeticity transition. This unique property could extend the applications of graphene to new horizons.