Nonequilibrium simulation method for the study of directed thermal processing.
Nonequilibrium simulation method for the study of directed thermal processing.
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用于研究定向热处理的非平衡模拟方法。
DOI：
10.1103/physrevb.39.10075
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Paulette Clancy
中科院分区：
文献类型：
--
作者：
Chokappa Dk;Cook Sj;Paulette Clancy
提出了一种非平衡态分子动力学计算机模拟方法，用于定向热处理，特别是激光退火的研究。使用称为“能量载体”的实体将强热梯度应用于基板，这些载体在给定的脉冲持续时间内以已知的强度-时间形状（此处为高斯）提供给定的能量影响。在随后的熔化和再凝固过程中计算基体的热力学、动力学和结构特性。熔体深度、界面温度和界面速度等特性作为时间的函数进行计算，从而可以预测过热和过冷的程度。根据这些结果，可以构造界面响应函数（界面速度-温度）。该函数显示了融化和冻结动力学的不对称性（前者明显更快），与最近的实验结果一致。讨论了该方法对能量载体、系统大小和脉冲持续时间建模的敏感性。本文给出了一个伦纳德-琼斯原子体系的结果，该体系有一个暴露的（100）fcc面，与硅的实验结果在定性上是一致的。
A nonequilibrium molecular-dynamics computer-simulation method is developed for the study of directed thermal processing, in particular laser annealing. A strong heat gradient is applied to a substrate using entities called ‘‘energy carriers,’’which supply a given energy fluence over a given pulse duration with a known intensity-time shape (Gaussian, here). The thermodynamic, kinetic, and structural properties of the substrate are calculated during the ensuing melting and resolidification. Properties such as the melt depth, interface temperature, and interface velocity are calculated as a function of time, allowing predictions of the extent of superheating and supercooling to be made. From these results, the interface response function (interface velocity versus temperature) can be constructed. This function shows an asymmetry of melting and freezing kinetics (the former being significantly faster), in accord with recent experimental results. The sensitivity of the method to the modeling of the energy carriers, the system size, and pulse duration is discussed. Results are presented for a system of Lennard-Jones atoms, with an exposed (100) fcc face, and shown to be in good qualitative agreement with experimental results for silicon.