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中文核心期刊

石墨烯辐照损伤及力学性能研究

STUDY ON IRRADIATION DAMAGE AND MECHANICAL PROPERTY OF GRAPHENE

  • 摘要: 石墨烯的加工和掺杂是其工程应用和性能开发的重要手段,离子辐照技术是实现上述目的的有效途径.利用分子动力学方法建立了硅离子辐照石墨烯和辐照后拉伸的数值模型.考虑辐照剂量、辐照能量和辐照角度这3个主要影响因素,研究了不同辐照条件下石墨烯的缺陷类型和数量,并分析了在辐照剂量影响下的拉伸破坏.结果表明:当辐照能量较小时,入射粒子会吸附在石墨烯表面.随着辐照能量的增大,入射粒子会穿透石墨烯而形成缺陷,当辐照能量到达一定值时,再无吸附原子.随着辐照剂量的增加,溅射原子和缺陷数目均增多,且缺陷类型以空位缺陷为主,其拉伸力学性能随着缺陷数量的增加而减小,二者近似成线性关系.辐照后石墨烯的拉伸破坏机理与完美石墨烯的有所不同,应力强化阶段明显缩短,缺陷带决定其起裂位置和断裂走向.

     

    Abstract: Processing and doping are important methods in the engineering application and development of graphene. Ion irradiation technology is an important approach to realize the processing and doping. The molecular dynamics model of graphene irradiated by Silicon neutral and the tensile model of defective graphene after irradiation damage are established. The defect types and quantities in graphene under different irradiation conditions, including ion dose, energy and angle, are analyzed and the tensile behaviors of defective graphene caused by different incident numbers of Si ions are also investigated. The conclusions are as follows:When the ion energy is small, incident particles will be adsorbed on the surface of graphene; with the increase of ion energy, incident particles can penetrate the target and form some defects; when the ion energy reaches a certain large value, there is no adsorbed atom. With the increase of the ion dose, the numbers of sputtering atoms and defects increase and the main defect is vacancy. The tensile mechanical properties of the corresponding defective graphene, such as tensile strength and limit strain, reduced with the increase of the defects number. The tensile failure mechanisms of the defective graphene caused by irradiation and the pristine graphene are different. The strengthened stage in the tensile curve of the former is shorter and the location of fracture initiation and the fault strike are dominated by the defect cluster.

     

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