Removal of defects in a colloidal crystal grown in an inverted pyramidal container by changing the external force

Keeping the formation of colloidal crystals by sedimentation in mind, we carry out Brownian dynamics simulations and study the crystallization of colloidal particles in an inverted pyramidal container. When an external force is added, the sedimentation of particles occurs and the particle density increases in the low region of the inverted pyramidal container. The crystallization of particles occurs and the face-centered cubic structure is formed in the container. When the force is large, the particles with the hexagonal close-packed structure are formed. Disordered particles are also formed and act as defects in bulk. After the sedimentation finishes, we decrease the force transiently. The defects in bulk are removed from the bulk. © 2015 The Japan Society of Applied Physics.Embargo Period 12 month