Ab initio calculation of ideal strength and phonon instability of graphene under tension

doi:10.1103/PhysRevB.76.064120

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	Ab initio calculation of ideal strength and phonon instability of graphene under tension
	Liu, Fang ; Ming, Pingbing ; Li, Ju
	2007-08-01
发表期刊	PHYSICAL REVIEW B
ISSN	1098-0121
卷号	76 期号:6 页码:7
摘要	Graphene-based sp(2)-carbon nanostructures such as carbon nanotubes and nanofibers can fail near their ideal strengths due to their exceedingly small dimensions. We have calculated the phonon spectra of graphene as a function of uniaxial tension by density functional perturbation theory to assess the first occurrence of phonon instability on the strain path, which controls the strength of a defect-free crystal at 0 K. Uniaxial tensile strain is applied in the x (nearest-neighbor) and y (second nearest-neighbor) directions, related to tensile deformation of zigzag and armchair nanotubes, respectively. The Young's modulus E=1050 GPa and Poisson's ratio nu=0.186 from our small-strain results are in good agreement with previous calculations. We find that in both x and y uniaxial tensions, phonon instabilities occur near the center of the Brillouin zone, at (epsilon(xx)=0.194, sigma(xx)=110 GPa, epsilon(yy)=-0.016) and (epsilon(yy)=0.266, sigma(yy)=121 GPa, epsilon(xx)=-0.027), respectively. Both soft phonons are longitudinal elastic waves in the pulling direction, suggesting that brittle cleavage fracture may be an inherent behavior of graphene and carbon nanotubes at low temperatures. We also predict that a phonon band gap will appear in highly stretched graphene, which could be a useful spectroscopic signature for highly stressed carbon nanotubes.
DOI	10.1103/PhysRevB.76.064120
语种	英语
WOS研究方向	Physics
WOS类目	Physics, Condensed Matter
WOS记录号	WOS:000249155200035
出版者	AMER PHYSICAL SOC
引用统计
文献类型	期刊论文
条目标识符	http://ir.amss.ac.cn/handle/2S8OKBNM/4773
专题	中国科学院数学与系统科学研究院
通讯作者	Liu, Fang
作者单位	1.Cent Univ Finance & Econ, Sch Appl Math, Beijing 100081, Peoples R China 2.Chinese Acad Sci, Acad Math & Syst Sci, ICMSEC, LSEC, Beijing 100080, Peoples R China 3.Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA
推荐引用方式 GB/T 7714	Liu, Fang,Ming, Pingbing,Li, Ju. Ab initio calculation of ideal strength and phonon instability of graphene under tension[J]. PHYSICAL REVIEW B,2007,76(6):7.
APA	Liu, Fang,Ming, Pingbing,&Li, Ju.(2007).Ab initio calculation of ideal strength and phonon instability of graphene under tension.PHYSICAL REVIEW B,76(6),7.
MLA	Liu, Fang,et al."Ab initio calculation of ideal strength and phonon instability of graphene under tension".PHYSICAL REVIEW B 76.6(2007):7.