6533b85bfe1ef96bd12bbd19

RESEARCH PRODUCT

Crystal growth kinetics in binary mixtures of model charged sphere colloids

subject

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From the formation of crystalline materials from their melts is at the heat of many important industrial processes. A rigorous and comprehensive understanding of the crystallization process, however, is still lacking, and its experimental and theoretical investigation has remained a considerable challenge. We studied the crystal growth velocities v of random composition body centred cubic (rc-bcc) colloidal crystals formed from a shear molten binary mixture of charged colloidal spheres suspended in deionized water. We used Bragg microscopy at constant particle number density n and as a function of the number fraction of large particles p. With increasing p the growth velocity v first drops steeply, then more slowly to yield an overall trapezoidal composition dependence. This dependence is not expected from the Wilson–Frenkel growth law for reaction limited growth which on the other hand correctly describes the number density dependence. The deviation possibly indicates a change in the kinetic prefactor.