中国激光, 2016, 43 (8): 0802004, 网络出版: 2016-08-10
氩、铝原子相互作用势的计算及其在飞秒激光烧蚀分子动力学模拟中的应用 下载: 741次
Calculation of Argon-Aluminum Interatomic Potential and Its Application in Molecular Dynamics Simulation of Femtosecond Laser Ablation
超快光学 飞秒激光烧蚀 分子动力学模拟 势能函数 结合能 ultrafast optics femtosecond laser ablation molecular dynamics simulation potential energy function binding energy
摘要
用分子动力学方法模拟飞秒激光在氩气(Ar)环境中烧蚀金属铝(Al)靶时,需要考虑氩原子和铝原子的相互作用。组合连接短程和长程2种势能函数,得到了Ar-Al相互作用的势能函数,并利用该相互作用势给出了相应小体系和小尺度下飞秒激光烧蚀的分子动力学模拟结果。该模型在Ar、Al原子距离较近时使用Ziegler-Biersack-Littmark(ZBL)势能函数,距离较远时使用Lennard-Jones(LJ)势能函数,中间距离则使用二次多项式函数。LJ势能函数的参数通过对Ar-Al结合能的拟合获得。将此Ar-Al相互作用势能函数用于氩气环境中飞秒激光烧蚀固体铝的分子动力学模拟,得到了皮秒量级时间延迟下的烧蚀动态图像和此过程中氩气温度、密度的演化规律。
Abstract
When molecular dynamics method is used to simulate femtosecond laser ablation of aluminum (Al) in argon (Ar) environment, the interaction of Ar and Al atoms needs to be considered. The potential function of Ar-Al interaction is obtained by combining two types of potential functions, including short range and long range. The molecular dynamics simulation results of femtosecond laser ablation at corresponding small system and scale are given by using the interaction potential. Ziegler-Biersack-Littmark (ZBL) potential function is used in shorter range of Ar-Al interatomic potential. Lennard-Jones (LJ) potential function is used in longer range. Second-order polynomial is used at the intermediate distance. The parameters of LJ potential function are obtained by fitting the Ar-Al binding energy. The Ar-Al interatomic potential function is used in molecular dynamics simulation of femtosecond laser ablation of aluminum in argon environment. The ablation dynamic images under picosecond time delay and the evolution laws of temperature and density of Ar in the process are obtained.
吴寒, 张楠, 何淼, . 氩、铝原子相互作用势的计算及其在飞秒激光烧蚀分子动力学模拟中的应用[J]. 中国激光, 2016, 43(8): 0802004. 吴寒, 张楠, 何淼, Shih Cheng-Yu. Calculation of Argon-Aluminum Interatomic Potential and Its Application in Molecular Dynamics Simulation of Femtosecond Laser Ablation[J]. Chinese Journal of Lasers, 2016, 43(8): 0802004.