de Jager Marjolein, Slaats Nena, Filion Laura
Soft Condensed Matter and Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, Netherlands.
J Chem Phys. 2024 Oct 7;161(13). doi: 10.1063/5.0228804.
The interplay between densification and positional ordering during the process of crystal nucleation is a greatly investigated topic. Even for the simplest colloidal model-hard spheres-there has been much debate regarding the potential foreshadowing of nucleation by significant fluctuations in either local density or local structure. Considering anisotropic particles instead of spheres adds a third degree of freedom to the self-organization process of crystal nucleation: orientational ordering. Here, we investigate the crystal nucleation of hard triangular prisms. Using Monte Carlo simulations, we first carefully determine the crystal-fluid coexistence values and calculate the nucleation barriers for two degrees of supersaturation. Next, we use brute force simulations to obtain a large set of spontaneous nucleation events. By studying the time evolution of the local density, positional ordering, and orientational ordering in the region in which the nucleus first arises, we demonstrate that all local order parameters increase simultaneously from the very start of the nucleation process. We thus conclude that we observe no precursor for the crystal nucleation of hard triangular prisms.
在晶体成核过程中，致密化与位置有序化之间的相互作用是一个受到广泛研究的课题。即使对于最简单的胶体模型——硬球体系，关于局部密度或局部结构的显著波动是否可能预示成核，也存在诸多争论。考虑使用各向异性颗粒而非球体，为晶体成核的自组织过程增加了第三个自由度：取向有序化。在此，我们研究硬三角棱柱的晶体成核过程。通过蒙特卡罗模拟，我们首先仔细确定晶体 - 流体共存值，并计算两种过饱和度下的成核势垒。接下来，我们使用强力模拟来获得大量自发成核事件。通过研究晶核最初出现区域内局部密度、位置有序化和取向有序化的时间演化，我们证明所有局部序参量从成核过程一开始就同时增加。因此，我们得出结论，对于硬三角棱柱的晶体成核，我们未观察到前驱体。
