Pseudo Hall鈥揚etch Strength Reduction in Polycrystalline Graphene
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- 作者：Zhigong Song ; Vasilii I. Artyukhov ; Boris I. Yakobson ; Zhiping Xu
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：April 10, 2013
- 年：2013
- 卷：13
- 期：4
- 页码：1829-1833
- 全文大小：382K
- 年卷期：v.13,no.4(April 10, 2013)
- ISSN：1530-6992
文摘
The fracture of polycrystalline graphene is explored by performing molecular dynamics simulations with realistic finite-grain-size models, emphasizing the role of grain boundary ends and junctions. The simulations reveal a 50% or more strength reduction due to the presence of the network of boundaries between polygonal grains, with cracks preferentially starting at the junctions. With a larger grain size, a surprising systematic decrease of tensile strength and failure strain is observed, while the elastic modulus rises. The observed crack localization and strength behavior are well-explained by a dislocation-pileup model, reminiscent of the Hall鈥揚etch effect but coming from different underlying physics.