Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Amundsen Street 106, 620016 Ekaterinburg, Russia.
J Chem Phys. 2013 Dec 14;139(22):224703. doi: 10.1063/1.4837695.
The crystal-liquid interfacial free energy γ has been calculated as a function of the crystal orientation in a molecular dynamics experiment in a system of Lennard-Jones (LJ) particles with a cutoff radius of the potential rc()=rc/σ=6.78 at a triple-point temperature Tt()=kBTt/ε=0.692 and temperatures above (in the region of the stable coexistence of liquid and solid phases) and below (metastable continuation of the coexistence curve of liquid and solid phases) the temperature Tt(). At T()=Tt(), for determining γ use was made of the method of cleaving potential. The temperature dependence of γ on the crystal-liquid coexistence curve has been determined by the Gibbs-Cahn thermodynamic integration method. In the region of stable phase coexistence (T()>Tt()) good agreement with the data of Davidchack and Laird [J. Chem. Phys. 118, 7651 (2003)] has been obtained with respect to the character of the temperature dependence of γ and the orientation anisotropy. In the region of metastable phase coexistence (T()<Tt()) at the approach to the endpoint of the melting line (TK()=0.529) (the existence of which was established first by Baidakov and Protsenko [Phys. Rev. Lett. 95, 015701 (2005)]) the interfacial free energy decreases, approaching at T()=TK() the orientation-averaged value γ0K()=γ0Kσ(2/ε)=0.365. The paper discusses the behavior of the excess interfacial energy, excess interfacial entropy and excess interfacial stress on the metastable extension of the melting line and close to T()=TK(*).
已经计算了在 Lennard-Jones (LJ) 粒子系统中，在温度 Tt()=kBTt/ε=0.692 和高于（在液相和固相稳定共存区域内）和低于（液相和固相共存曲线的亚稳延续）温度 Tt()=kBTt/ε=0.692 的温度下，作为晶体取向函数的晶-液界面自由能 γ。在 T()=Tt()=0.692 时，通过切割势的方法确定了 γ。通过 Gibbs-Cahn 热力学积分方法确定了 γ 随晶-液共存曲线的温度依赖性。在稳定相共存区域（T()>Tt()=0.692），与 Davidchack 和 Laird [J. Chem. Phys. 118, 7651 (2003)] 的数据相比，γ 的温度依赖性和取向各向异性的特征吻合良好。在亚稳相共存区域（T()<Tt()=0.692），在接近熔点线终点（TK()=0.529）时（熔点线的存在首先由 Baidakov 和 Protsenko [Phys. Rev. Lett. 95, 015701 (2005)] 建立），界面自由能减小，在 T()=TK()=0.529 时趋近于取向平均值 γ0K()=γ0Kσ(2/ε)=0.365。本文讨论了在亚稳熔点延伸和接近 T()=TK()=0.529 时，过剩界面能、过剩界面熵和过剩界面应力的行为。
