Novel liquid- and crystal-droplet phases on highly charged colloidal suspensions

Brownian-dynamics simulations are performed on highly charged colloidal suspensions by employing an effective attractive force between colloids proposed recently by Tokuyama (Phys. Rev. E 59 (1999) R2550; Phys. Rev. E 58 (1998) R2729). In addition to a gas phase, two novel droplet phases are shown to exist even in dilute suspensions, a liquid-droplet phase and a crystal-droplet phase. The structure of these droplets is fully investigated by the analyses of the radial distribution function. The simulation results also suggest that each transition line between phases is determined only by the condition that the potential minimum is constant.