Density fluctuation dynamics in a screened Coulomb colloid: Comparison of the liquid and bcc crystal phases

Abstract

Inelastic light scattering from particle number density fluctuations was carried out on a suspension of 0.109 μ diam sulfonated polystyrene microspheres exhibiting coexisting colloidal liquid and body-centered-cubic single crystalline phases. Comparison of the first cumulants of the decay of the density–density correlation function in the two phases reveals that the wave vector dependence in the liquid exhibits many features in common with that for longitudinal 110 lattice vibrations in the crystal.