Wang Ya-Shen, Zhang Xin, Liang Zun, Liang Hong-Tao, Yang Yang, Laird Brian B
State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
J Chem Phys. 2024 Aug 28;161(8). doi: 10.1063/5.0216556.
By employing non-equilibrium molecular dynamics (NEMD) simulations and time-dependent Ginzburg-Landau (TDGL) theory for solidification kinetics [Cryst. Growth Des. 20, 7862 (2020)], we predict the kinetic coefficients of FCC(100) crystal-melt interface (CMI) of soft-spheres modeled with an inverse-sixth-power repulsive potential. The collective dynamics of the local interfacial liquid phase at the equilibrium FCC(100) CMIs are calculated based on a recently proposed algorithm [J. Chem. Phys. 157, 084 709 (2022)] and are employed as the resulting parameter that eliminates the discrepancy between the predictions of the kinetic coefficient using the NEMD simulations and the TDGL solidification theory. A speedup of the two modes of the interfacial liquid collective dynamics (at wavenumbers equal to the principal and the secondary reciprocal lattice vector of the grown crystal) is observed. With the insights provided by the quantitative predictive theory, the variation of the solidification kinetic coefficient along the crystal-melt coexistence boundary is discussed. The combined methodology (simulation and theory) presented in this study could be further applied to investigate the role of the inter-atomic potential (e.g., softness parameter s = 1/n of the inverse-power repulsive potential) in the kinetic coefficient.
通过采用非平衡分子动力学（NEMD）模拟和用于凝固动力学的含时金兹堡 - 朗道（TDGL）理论[《晶体生长与设计》20, 7862 (2020)]，我们预测了用六次方反比排斥势建模的软球的面心立方（FCC）(100) 晶体 - 熔体界面（CMI）的动力学系数。基于最近提出的一种算法[《化学物理杂志》157, 084709 (2022)]计算了平衡FCC(100) CMI处局部界面液相的集体动力学，并将其用作消除使用NEMD模拟预测的动力学系数与TDGL凝固理论之间差异的结果参数。观察到界面液体集体动力学的两种模式（在波数等于生长晶体的主倒易晶格矢量和次倒易晶格矢量处）的加速。借助定量预测理论提供的见解，讨论了凝固动力学系数沿晶体 - 熔体共存边界的变化。本研究中提出的联合方法（模拟和理论）可进一步应用于研究原子间势（例如，反比排斥势的软度参数s = 1/n）在动力学系数中的作用。
