Homogeneous Nucleation of Nearly-hard-sphere Colloidal Crystals from the Liquid: Measurements and Modeling

Abstract

Understanding crystal nucleation in colloidal systems remains fundamentally challenging de- spite decades of research, with persistent discrepancies between experimental measurements and theoretical predictions. Using confocal microscopy, we directly observe homogeneous crystal nucleation in nearly hard-sphere colloids and compare this results with Brownian dynam- ics simulations. Our measurements of critical nucleus size, interfacial energy, and nucleation rates demonstrate excellent agreement between experiment and simulation, validating Classical Nucle- ation Theory (CNT) without requiring enhanced sampling techniques. Moreover, crystal morphol- ogy analyzes reveal a branched crystal phase before transitioning to compact spherical nuclei, which is different from the CNT assumption10. Our findings resolve long-standing nucleation rate dis- crepancies in this system while highlighting that experimental approaches currently provide a wider data window than computationally practical simulations, especially for rare nucleation events near melting conditions.