Formation of a crystal of Brownian particles under a uniform external force

To keep the formation of colloidal crystal under a centrifugation in mind, we study ordering of Brownian particles under a uniform external force. When the force is added to Brownian particles distributing uniformly in the system, the particles drift and the density of particles near walls increases. Ordering of particles on the walls occurs at first and ordering in bulk occurs in succession. In bulk, both the clusters with face-centered cubic structure and those with the hexagonal close-packed structure appear. The distribution of cluster sizes changes with the direction of external force. DOI:10.1103/PhysRevE.87.032403