Crystallization in suspensions of hard spheres and turbidity

The dynamics of crystallization have been investigated for suspensions of hard spheres by small angle light scattering, direct imaging, and Bragg scattering. This work reports preliminary but complementary measurements of turbidity during crystallization. The change in turbidity correlates with small angle light scattering for the smaller volume fractions studied, where the signal is strong. However, an initial exponential time dependence in turbidity is observed, which has a decay time independent of the sample volume fraction. This signal dominates at larger volume fractions where small angle light scattering measurements are weak and Bragg studies are more easily performed. We identify this initial transient decay with a laser-induced heating of the sample.