Structure, energy, and structural transformations of graphene grain boundaries from atomistic simulations
Structure, energy, and structural transformations of graphene grain boundaries from atomistic simulations
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DOI：
10.1016/j.carbon.2011.01.063
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发表时间：
2011-06-01
期刊：
影响因子：
10.9
通讯作者：
Chang, Chien-Cheng
中科院分区：
文献类型：
--
作者：
Liu, Te-Huan;Gajewski, Grzegorz;Chang, Chien-Cheng
在化学气相沉积生长过程中，通常将畴/晶界引入石墨烯中。在这里，我们进行了一系列的混合分子动力学模拟研究的结构，能量，和对称倾斜晶界的石墨烯的结构转变。晶界包括刃位错阵列，位错密度随着晶界取向差角的增加而增加。位错在扶手椅取向的晶界包含一个边缘共享五边形/七边形缺陷，而位错在扶手椅取向的晶界包含两个成对的五边形/七边形缺陷。在某些晶界中，由于位错的存在，存在面外屈曲。在过渡区（Z字形和扶手椅取向的晶界之间的区域），晶界结构的特点是Z字形和扶手椅晶界的复杂混合物。我们还讨论了在添加或去除碳原子时发生的晶界转变和迁移，在我们所有的研究类型的晶界。(C)2011爱思唯尔有限公司保留所有权利。
Domain/grain boundaries are often introduced into graphene during chemical vapor deposition growth processes. Here, we performed a series of hybrid molecular dynamics simulations to study the structures, energies, and structural transformations of symmetric tilt grain boundaries of graphene. The grain boundary comprises an array of edge dislocations, with the dislocation density increasing upon increasing the grain boundary misorientation angle. The dislocation in the zigzag-oriented grain boundary contains an edge-sharing pentagon/heptagon defect, whereas the dislocation in the armchair-oriented grain boundary contains two paired pentagon/heptagon defects. In some grain boundaries, out-of-plane buckling exists due to the presence of dislocations. In the transition region (the region between the zigzag- and armchair-oriented grain boundaries), the grain boundary structures feature complex mixtures of both zigzag and armchair grain boundaries. We also discuss the grain boundary transformations and migrations that occur upon adding or removing carbon atoms at the grain boundaries for all of our investigated types of grain boundaries. (C) 2011 Elsevier Ltd. All rights reserved.