From compact to fractal crystalline clusters in concentrated systems of monodisperse hard spheres

Abstract

We address the crystallization of monodisperse hard spheres in terms of the properties of finite- size crystalline clusters. By means of large scale event-driven Molecular Dynamics simulations, we study systems at different packing fractions ϕ ranging from weakly supersaturated state points to glassy ones, covering different nucleation regimes. We find that such regimes also result in different properties of the crystalline clusters: compact clusters are formed in the classical-nucleation-theory regime (ϕ \leq 0.54), while a crossover to fractal, ramified clusters is encountered upon increasing packing fraction (ϕ \geq 0.56), where nucleation is more spinodal-like. We draw an analogy between macroscopic crystallization of our clusters and percolation of attractive systems to provide ideas on how the packing fraction influences the final structure of the macroscopic crystals. In our previous work (Phys. Rev. Lett., 106, 215701, 2011), we have demonstrated how crystallization from a glass (at ϕ > 0.58) happens via a gradual (many-step) mechanism: in this paper we show how the mechanism of gradual growth seems to hold also in super-saturated systems just above freezing showing that static properties of clusters are not much affected by dynamics.

Soft Matter, 2012

References in corpus (7)

• Colloidal Gels: Equilibrium and Non-Equilibrium Routes
• Probing the equilibrium dynamics of colloidal hard spheres above the mode-coupling glass transition
• Crystallization of hard-sphere glasses
• Phase behavior of a fluid with competing attractive and repulsive interactions
• Colloidal systems with competing interactions: from an arrested repulsive cluster phase to a gel
• Equilibrium phase behavior of polydisperse hard spheres
• Phase behavior and far-from-equilibrium gelation of charged attractive colloids

Cited by in corpus (7)

• The role of local structure in dynamical arrest
• Crystal nucleation as the ordering of multiple order parameters
• Colloidal Hard Spheres: Triumphs, Challenges and Mysteries
• Morphology of clusters of attractive dry and wet self-propelled spherical particle suspensions
• Non-classical pathways of crystallization in colloidal systems
• Homogeneous Nucleation of Sheared Liquids: Advances and Insights from Simulations and Theory
• Orientational order and morphology of clusters of self-assembled Janus swimmers