Melting of metastable crystallites in charge-stabilized colloidal suspensions.

We use low-frequency electrophoresis to crystallize monodisperse charge-stabilized colloidal suspensions. Rather than reverting directly to their equilibrium fluid state when the field is removed, some suspensions retain long-lived metastable crystallites whose evolution we track using highresolution digital video microscopy. To quantify the decay of order in this system we introduce an empirical criterion for distinguishing spheres in the crystal from those in the fluid.