Fayen Etienne, Jagannathan Anuradha, Foffi Giuseppe, Smallenburg Frank
Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.
J Chem Phys. 2020 May 29;152(20):204901. doi: 10.1063/5.0008230.
One versatile route to the creation of two-dimensional crystal structures on the nanometer to micrometer scale is the self-assembly of colloidal particles at an interface. Here, we explore the crystal phases that can be expected from the self-assembly of mixtures of spherical particles of two different sizes, which we map to (additive or non-additive) hard-disk mixtures. We map out the infinite-pressure phase diagram for these mixtures using Floppy Box Monte Carlo simulations to systematically sample candidate crystal structures with up to 12 disks in the unit cell. As a function of the size ratio and the number ratio of the two species of particles, we find a rich variety of periodic crystal structures. Additionally, we identify random tiling regions to predict random tiling quasicrystal stability ranges. Increasing non-additivity both gives rise to additional crystal phases and broadens the stability regime for crystal structures involving a large number of large-small contacts, including random tilings. Our results provide useful guidelines for controlling the self-assembly of colloidal particles at interfaces.
在纳米到微米尺度上创建二维晶体结构的一种通用方法是胶体颗粒在界面处的自组装。在这里，我们探索了两种不同尺寸球形颗粒混合物自组装可能产生的晶相，我们将其映射到（加和性或非加和性）硬磁盘混合物。我们使用软盘盒蒙特卡罗模拟绘制这些混合物的无限压力相图，以系统地对晶胞中最多有12个磁盘的候选晶体结构进行采样。作为两种颗粒的尺寸比和数量比的函数，我们发现了丰富多样的周期性晶体结构。此外，我们识别随机平铺区域以预测随机平铺准晶体的稳定性范围。增加非加和性既会产生额外的晶相，又会拓宽涉及大量大小接触的晶体结构（包括随机平铺）的稳定区域。我们的结果为控制界面处胶体颗粒的自组装提供了有用的指导。
