Brownian dynamics simulation of the crystallization dynamics of charged colloidal particles

Crystal formation process of charged colloidal particles is investigated using Brownian dynamics (BD) simulations. The particles are assumed to interact with the pair-additive repulsive Yukawa potential. The time evolution of crystallization process and the crystal structure during the simulation are characterized by means of the radial distribution functions (RDF) and mean square displacement (MSD). The simulations show that when the interaction is featured with long-range, particles can spontaneously assemble into body-centered-cubic (BCC) arrays at relatively low particle number density. When the interaction is short-ranged, with increasing the number density particles become trapped into a stagnant disordered configuration before the crystallization could be actualized. The simulations further show that as long as the trapped configurations are bypassed, the face-centered-cubic (FCC) structures can be achieved and are actually more stable than BCC structures.

Radial distribution function and snapshots from the Brownian dynamics simulation of the BCC–FCC transition.Figure optionsDownload high-quality image (95 K)Download as PowerPoint slideResearch highlights
► Charged colloidal crystallization is studied by three-dimensional BD simulation.
► BCC crystals could evolve spontaneously for long-range interaction.
► For short-range interaction no crystal can evolve spontaneously in simulation.
► For short-range interaction FCC structure could transit from BCC structure.