标题： 淬火无序对软胶体系统相变动力学和路径的影响 显示英文标题

标题： Effects of quenched disorder on the kinetics and pathways of phase transition in a soft colloidal system

摘要： 尽管杂质在现实世界和实验系统中是不可避免的，但大多数关于成核的数值研究都集中在纯（无杂质）系统上。 因此，杂质在相变中的作用仍然知之甚少，尤其是在具有一个或多个亚稳中间相的复杂自由能景观系统中。 在本研究中，我们采用了蒙特卡洛模拟来研究静态杂质（淬火无序）的不同尺度和表面形态对高斯核心模型（GCM）系统中成核机制和动力学的影响，GCM 是一种软胶体系统的模型。 我们首先探讨了成核自由能势垒和临界团簇大小如何受到固定粒子比例（$f_{\rm p}$）和固定团簇大小（$n_{\rm p}$）的影响。 随着$f_{\rm p}$的增加，成核自由能势垒和临界团簇大小急剧上升，但随着$n_{\rm p}$的增长而减少，最终接近均匀成核极限。 在研究表面形貌对成核动力学的影响时，我们观察到随着面心立方（FCC）、体心立方（BCC）和简单立方（SC）结构的球形固定团簇（称为“种子”）尺寸的增加，成核势垒显著降低，其中 BCC 表现出最大的促进作用。 有趣的是，具有随机表面粗糙度的种子对成核动力学影响很小。 此外，最终晶体相中粒子的多型性身份同时受到种子表面形貌和系统尺寸的影响。 本研究进一步提供了关于基底诱导的局部结构涨落与最终晶体相中多型性身份选择之间复杂关系的重要见解，这对于理解和控制实验中的结晶过程至关重要。 显示英文摘要

摘要： Although impurities are unavoidable in real-world and experimental systems, most numerical studies on nucleation focus on pure (impurity-free) systems. As a result, the role of impurities in phase transitions remains poorly understood, especially for systems with complex free energy landscapes featuring one or more metastable intermediate phases. In this study, we employed Monte-Carlo simulations to investigate the effects of static impurities (quenched disorder) of varying length scales and surface morphologies on the nucleation mechanism and kinetics in the Gaussian Core Model (GCM) system, a model for soft colloidal systems. We first explored how the nucleation free energy barrier and critical cluster size are influenced by the fraction of pinned particles ($f_{\rm p}$) and the pinned cluster size ($n_{\rm p}$). Both the nucleation free energy barrier and critical cluster size increase sharply with increasing $f_{\rm p}$ but decrease as $n_{\rm p}$ grows, eventually approaching the homogeneous nucleation limit. On examining the impact of surface morphology on nucleation kinetics, we observed that the nucleation barrier significantly decreases with increasing the spherical pinned cluster (referred to as "seed") size of face-centred cubic (FCC), body-centred cubic (BCC), and simple cubic (SC) structures, with BCC showing the greatest facilitation. Interestingly, seeds with random surface roughness had little effect on nucleation kinetics. Additionally, the polymorphic identity of particles in the final crystalline phase is influenced by both seed surface morphology and system size. This study further provides crucial insights into the intricate relationship between substrate-induced local structural fluctuations and the selection of the polymorphic identity in the final crystalline phase, which is essential for understanding and controlling crystallization processes in experiments.