Growing Binary Hard Sphere Crystals

Computer simulations of the fluid-to-solid phase transition in the hard sphere system were instrumental for our understanding of the crystallization process. While colloid experiments and theory have been predicting the stability of several binary crystals for many years, simulations were not successful to confirm this phenomenon. Mixtures, such as the binary hard sphere fluid, are also common model systems for research in glass physics, and it is crucial to know about the presence of any crystallization transition. Here, we report the growth of binary crystals isostructural to Laves phases, AlB$_2$, and NaZn$_{13}$ in simulation directly from the fluid. We analyze particle kinetics during Laves phase growth by comparing event-driven molecular dynamics simulations with and without swap moves that speed up diffusion. Finally, we present packing fraction--size ratio state diagrams in the vicinity of the stability regions of these three binary hard sphere crystals.