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-BiersackLittmark(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。
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 AI interatomic potential. Lennard-Jones （L J） 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-A1 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.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2016年第8期110-116,共7页
Chinese Journal of Lasers
基金
国家自然科学基金(61137001
11274185)
国家留学基金(201406200066)
关键词
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
