Short laser pulse nanostructuring of metals: direct comparison of molecular dynamics modeling and experiment
Short laser pulse nanostructuring of metals: direct comparison of molecular dynamics modeling and experiment
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DOI：
10.1007/s00339-013-7656-9
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发表时间：
2013-06-01
影响因子：
2.7
通讯作者：
Schulz, W.
中科院分区：
文献类型：
--
作者：
Ivanov, D. S.;Kuznetsov, A. I.;Schulz, W.
利用超短激光脉冲对材料进行纳米加工涉及到许多并行的基本物理过程。然而，由于激活的时间和空间尺度不同，这些过程一方面难以在单一计算模型的框架内进行研究，另一方面又无法在实验分析中分离出来。在他们的详细研究中，短激光脉冲诱导的物质非平衡态的瞬态特征阻碍了连续介质方法的适用性，但经典的分子动力学模拟通常受到系统尺寸的限制。在这项工作中，基于分子动力学的模型耦合于光激发自由载流子动力学的连续体描述，并在并行算法中实现，扩展到实验中直接可获得的尺度。这使得第一次可以与实验数据进行直接比较。从纳米结构生成过程中相互竞争过程的复杂动力学角度分析了短激光脉冲表面纳米结构形成的基本机理。模型和实验结果吻合良好，为纳米颗粒结构的制备和表面亚图像化提供了新的机会。
Nanoprocessing of materials using ultrashort laser pulses involves a number of concurrent fundamental physical processes. Due to different time and spatial scales of activation, however, these processes are difficult to study within the frames of a single computational model on one hand, and yet not possible to isolate in the experimental analysis on the other hand. In their detailed investigation, the transient character of the nonequilibrium states of matter induced with a short laser pulse hampers the applicability of continuum approaches, but classical molecular dynamics simulations are usually limited in the system sizes. In this work, a molecular dynamics based model coupled to a continuum description of the photo-excited free carrier's dynamics and implemented in parallel algorithm is extended to the scale directly accessible in the experiment. This allows for the first time a direct comparison to experimental data. The essential mechanisms responsible for the short laser pulse surface nanostructuring are analyzed in the complex dynamics of competing processes simultaneously involved into the nanostructures generation process. The modeling and experiment show a very good agreement and predict a new opportunity for fabrication of nanoparticle structures and the surface subpatterning.