Growth pathway of an AB₂-type colloidal alloy during colloidal heteroepitaxy

Ideally, the final crystal structures are determined by the minimization of free energy. However, the actual growth pathway, which is governed by growth conditions, also influences the resulting structure. In our previous experimental study [J. Nozawa et al., Cryst. Growth Des., 2025, 25, 7309-7316], we observed the formation of a binary colloidal alloy on a substrate during colloidal heteroepitaxy. We experimentally investigated how the growth pathway of an AB₂ type colloidal alloy depends on the growth conditions, and demonstrated how the growth velocity and nucleation rate are influenced by the composition of two particle types with different sizes. Based on these experiments, we conducted simulations, using a short-range interaction potential, similar to the Asakura-Oosawa potential, to model the depletion force. We examined the combinations of particle sizes that efficiently produce the AB₂-type colloidal alloy on the substrate and how the growth process affects the final structure.