• 文献标题:   Uniaxially Strained Graphene: Structural Characteristics and G-Mode Splitting
  • 文献类型:   Article
  • 作  者:   KALOSAKAS G, LATHIOTAKIS NN, PAPAGELIS K
  • 作者关键词:   graphene, uniaxial strain, bond length, bond angle, gband splitting, density functional theory, molecular dynamic
  • 出版物名称:   MATERIALS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   1
  • DOI:   10.3390/ma15010067
  • 出版年:   2022

▎ 摘  要

The potential use of graphene in various strain engineering applications requires an accurate characterization of its properties when the material is under different mechanical loads. In this work, we present the strain dependence of the geometrical characteristics at the atomic level and the Raman active G-band evolution in a uniaxially strained graphene monolayer, using density functional theory methods as well as molecular dynamics atomistic simulations for strains that extend up to the structural failure. The bond length and bond angle variations with strain, applied either along the zigzag or along the armchair direction, are discussed and analytical relations describing this dependence are provided. The G-mode splitting with strain, as obtained by first principles' methods, is also presented. While for small strains, up to around 1%, the G-band splitting is symmetrical in the two perpendicular directions of tension considered here, this is no longer the case for larger values of strains where the splitting appears to be larger for strains along the zigzag direction. Further, a crossing is observed between the lower frequency split G-mode component and the out-of-plane optical mode at the Gamma point for large uniaxial strains (>20%) along the zigzag direction.