Abstract
AbstractLaser ablation is often simulated by the two-temperature model in which electrons are assumed to be thermalized by laser irradiation, while an explicit representation of interaction between laser-field and electrons is challenging but beneficial as being free from any adjustable parameters. Here, an ab initio method based on the time-dependent density functional theory (TDDFT) in which electron-ion dynamics under a laser field are numerically simulated is examined as a tool for simulating femtosecond laser processing of metals. Laser-induced volume expansion in surface normal directions of Cu(111) and Ni(111) surfaces are simulated by using repeating slab models. The amount of simulated volume expansion is compared between Cu(111) and Ni(111) slabs for the same laser pulse conditions, and the Ni slab is found to expand more than the Cu slab despite the smaller thermal expansion coefficient of Ni compared with Cu. The analyzed electronic excitation and lattice motion were compared to those in the two-temperature model. The threshold fluence to release surface Cu atom deduced from current TDDFT approach is found to be comparable to those of Cu ablation reported experimentally.
Funder
Japan Society for the Promotion of Science
New Energy and Industrial Technology Development Organization
Publisher
Springer Science and Business Media LLC
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献