Confocal Microscopy of Hard Sphere Crystal Growth

Classical crystal growth is determined by the competition between chemical potential differences and surface tension. We use confocal microscopy to measure three dimensional crystal growth in a density matched suspension of PMMA-PHSA colloidal particles. The crystal is nucleated from a surface template that forces growth of face-centered-cubic crystals. The growing crystal surface is rough on the scale of several particle diameters, but the average growth rate is well described by the classical Wilson-Frenkel growth law. The local growth rate does depend on the roughness of the surface, however, and this growth rate variation provides a measure of interfacial surface tension.