Hard Sphere Crystallization near Large Spherical Impurities (THESIS VERSION)

Abstract

Impurities affect the nucleation, growth and structure of crystals. We report the effect of large spherical poly-methyl-methacrylate impurities on the crystal nucleation and growth of monodisperse, hard poly-methyl-methacrylate colloids in a density and optically matching apolar solvent mixture. Crystallization, initiated either at the sample wall or at the impurity surface, was studied by imaging sequences of two-dimensional xy-slices in the plane of the impurity’s centre with a laser scanning confocal microscope. Sufficiently large impurities can induce crystal nucleation. During crystal growth, impurities function as large immovable objects that eventually slow down growth. The resulting structure of the obtained crystals is characterized by relatively small grains.