石墨烯SW缺陷的运动路径

Transition path of SW defect in graphene

为分析石墨烯中的缺陷对其物理性能的影响,在原子尺度上研究了石墨烯中Stone Wales(SW)缺陷的两种主要运动:一种是从完美状态到有一个SW缺陷的稳定状态的生成过程;另一种是在一个SW缺陷的稳定状态中SW缺陷位置的变化过程。利用Nudged elastic band(NEB)方法得到SW缺陷生成路径、势垒和过渡态。另外用NEB方法模拟了SW缺陷的位置变化过程,并得到了该运动过程的过渡态的原子结构图像。模拟结果显示:SW缺陷的运动发生概率很小,要先变为完美状态,即先湮灭,再重新生成。

To analyze the effect of defects in graphene on the physical properties of graphene, two kinds of main motions of Stone Wales(SW) in graphene were studied on the atomic scale. One is the generation process from the perfect state to the steady state with one SW defect. The other is the change process of SW defect position in the steady state with a SW defect. Minimum energy path, potential barrier and transition state of the generation of SW defect were gained by nudged elastic band method(NEB). In addition, NEB method was used to simulate position change process of SW defect, and atomic structure image of transition state in the motion process was obtained. The results show that SW defect has a small probability of moving without annihilation. It can be regenerated through becoming the perfect state first, i.e. annihilating first.