KINETICS OF CRYSTALLIZATION IN A SHEARING COLLOIDAL SUSPENSION

We report the kinetics of crystallization as observed in simulations of a charged colloidal suspension under shear. We find that the imposed shear how inhibits crystal nucleation. Crystallization was only observed for shear rates at or below gamma tau(0) = 0.07 (where tau(0) is the time required for a particle to diffuse the averge interparticle distance in a dilute suspension). Under the influence of these low shear rates the suspension crystallizes into a single shear-aligned crystal, as opposed to the polycrystalline structure found in the absence of shear flow. Crystal growth is found to be proportional to the effective supercooling, as measured from the melting temperature of the shearing crystal. We conclude that, by analogy with the case of crystallization at zero shear, the effective supercooling provides an operational measure of the ''thermodynamic'' stability of the shearing crystal.