Abstract: The influence of ion irradiation on graphene’s mechanical properties was investigated using molecular dynamics simulations (MD) including Young’s modulus, stress and strain. Incident ions were C ions with 1 keV, and the situations under different incident doses were studied, including 2.00×10¹³, 6.01×10¹³, 1.00×10¹⁴ and 2.00×10¹⁴cm^-2, respectively. The results show that defects, such as single, double vacancies and complex defects, are introduced by bombardment. They have a great effect on graphene’s mechanical properties, for example, two single vacancies can make Young’s modulus decreasing from 780.19 GPa to 128.77 GPa, and stress from 161.81 GPa to 30.85 GPa, compared with perfect graphene. The more defects in graphene, the effect will be greater. In addition, the physical mechanism of graphene’s deformation and cracking was taken over.

Key words: graphene, mechanical properties, irradiation, molecular dynamics

摘要： 利用分子动力学方法研究了不同剂量的碳离子辐照石墨烯产生损伤后对其拉伸力学性能的影响, 包括应力?应变曲线、杨氏模量以及拉伸强度等。入射离子能量为1 keV, 入射剂量分别为2.00×10¹³, 6.01×10¹³, 1.00×10¹⁴ and 2.00×10¹⁴cm^-2。结果表明, 离子辐照后产生了单空位缺陷、双空位缺陷及复杂缺陷等, 这些缺陷对石墨烯的力学性能产生了显著影响, 如剂量为2.00×10¹³cm^-2时, 石墨烯中只存在两个单空位缺陷, 但与完美石墨烯相比, 杨氏模量却从780.19 GPa减小到128.77 GPa, 拉伸强度也从161.81 GPa变为30.85 GPa, 并且缺陷个数越多, 力学性能越差。另外, 对辐照导致样品变形以及断裂的物理机制也进行了讨论。

关键词: 石墨烯, 力学性能, 辐照, 分子动力学