de Jager Marjolein, Smallenburg Frank, Filion Laura
Soft Condensed Matter, Debye Institute of Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.
J Chem Phys. 2023 Oct 7;159(13). doi: 10.1063/5.0161356.
The interplay between crystal nucleation and the structure of the metastable fluid has been a topic of significant debate over recent years. In particular, it has been suggested that even in simple model systems such as hard or charged colloids, crystal nucleation might be foreshadowed by significant fluctuations in local structure around the location where the nucleus first arises. We investigate this using computer simulations of spontaneous nucleation events in both hard and charged colloidal systems. To detect local structural variations, we use both standard and unsupervised machine learning methods capable of finding hidden structures in the metastable fluid phase. We track numerous nucleation events for the face-centered cubic and body-centered cubic crystals on a local level and demonstrate that all signs of crystallinity emerge simultaneously from the very start of the nucleation process. We thus conclude that we observe no precursor for the crystal nucleation of hard and charged colloids.
近年来，晶体成核与亚稳态流体结构之间的相互作用一直是一个备受争议的话题。特别是，有人提出，即使在硬胶体或带电胶体等简单模型系统中，晶体成核可能会在核最初出现位置周围的局部结构中出现显著波动而预先显示出来。我们通过对硬胶体和带电胶体系统中的自发成核事件进行计算机模拟来研究这一问题。为了检测局部结构变化，我们使用了能够在亚稳态流体相中找到隐藏结构的标准和无监督机器学习方法。我们在局部层面上跟踪了面心立方和体心立方晶体的大量成核事件，并证明结晶的所有迹象从成核过程一开始就同时出现。因此，我们得出结论，我们没有观察到硬胶体和带电胶体晶体成核的前兆。
