Modes of motion of a colloidal crystal

The dynamical behavior of charge-stabilized colloidal crystals that consist of polystyrene spheres in highly deionized water is determined by solvent flow mediated interactions and by ionic effects. The expression of these effects strongly depends on the polarization of crystal waves. Using dynamic light scattering we trace all but the fastest known modes of motion and evaluate the influence of ion friction. We find a new mode that we ascribe to ion retardation. Our experiments point to the importance of electrophoresis for microscopic colloid dynamics