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位错是石墨烯材料中的一种重要结构缺陷.本文通过基于离散晶格方法的virial局部应变研究了石墨烯位错周围应变场.结果表明两种原子级virial局部应变,即无限小应变和有限应变,与位错弹性理论预测结果吻合较好,从而证明了virial应变分析方法的有效性.然而这两种应变存在微小差异,该差异可以用来显示位错芯域的原子结构.近邻环境对这种应变差异存在影响,根源在于不同的近邻环境对位错芯域局部变形的敏感程度不同:与次近邻环境相比,最近邻环境计算范围较小,计算出的应变差异对局部变形更加敏感.最后,提出近邻位移参数——一种显示石墨烯位错的新方法,该参数可以清晰地显示出石墨烯位错的5|7结构,并能够反映出褶皱引起的结构变化.
Dislocation is an important structural defect in graphene materials.In this paper, the strain field around the dislocations of graphene was investigated by virial local strain based on the discrete lattice method.The results show that the two kinds of atomic virial local strain, ie, infinitely small strain and The finite strain, which is in good agreement with the prediction of dislocation elastic theory, proves the validity of the virial strain analysis method. However, there is a slight difference between the two strains, which can be used to show the atomic structure of the dislocation core. The reason for this difference in strain is that the sensitivity of the different adjacent environments to the local deformation of the dislocation core is different: the calculation range of the nearest neighbor is smaller than that of the second nearest neighbor, and the calculated strain difference has more influence on the local deformation Sensitive.Finally, we propose a new neighbor displacement parameter, a new method of displaying graphene dislocations, which can clearly show the 5 7 structure of graphene dislocations and reflect the structural changes caused by the wrinkles.