The formation mechanism of multiple vacancies and amorphous graphene under electron irradiation.
The formation mechanism of multiple vacancies and amorphous graphene under electron irradiation.
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DOI：
10.1039/c5nr00552c
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发表时间：
2015-04
期刊：
影响因子：
6.7
通讯作者：
Ruiqi Zhao;J. Zhuang;Zilin Liang;T. Yan;F. Ding
中科院分区：
文献类型：
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作者：
Ruiqi Zhao;J. Zhuang;Zilin Liang;T. Yan;F. Ding
采用长时间非平衡态分子动力学模拟方法，系统研究了电子辐照下石墨烯中多空位（Vns）的演化规律，n值从4变化到40.模拟结果表明，在小的n的情况下，Vns形成海克尔石，而形成空穴n的增加。海克尔石的规模，其特征在于五边形-七边形对的数量，随n线性增长。这种线性关系可以解释为补偿由Vns引起的缺失面积的结果，以便通过自愈来保持完美sp（2）网络的面积。除此之外，黑克石与缺失原子密度的比例预计为Sh = 6Dn，其中Sh和Dn分别是非六边形环和缺失原子的百分比。该研究为EI作用下非晶石墨烯的形成提供了直观的图像，并对机理有了定量的认识。
The evolution of multiple vacancies (Vns) in graphene under electron irradiation (EI) was explored systematically by long time non-equilibrium molecular dynamics simulations, with n varying from 4 to 40. The simulations showed that the Vns form haeckelites in the case with small n, while forming holes as n increases. The scale of the haeckelites, characterized by the number of pentagon-heptagon pairs, grows linearly with n. Such a linear relationship can be interpreted as a consequence of compensating the missing area, caused by the Vns, in order to maintain the area of the perfect sp(2) network by self-healing. Beyond that, the scale of the haeckelite vs. the density of missing atoms is predicted to be Sh ∼ 6Dn, where Sh and Dn are the percentage of non-hexagonal rings and missing atoms, respectively. This study provides an intuitive picture of the formation of amorphous graphene under EI and the quantitative understanding of the mechanism.