DENSITY-FUNCTIONAL THEORY OF ORDERING IN CHARGE-STABILIZED COLLOIDAL DISPERSIONS

We employ a simple density functional approach to predict the phase diagram of charge-stabilized colloidal dispersions consisting of bcc, fcc, and liquid phases. The systems are modeled to consist of charged hard sphere macroions interacting through a screened Coulomb potential for which the rescaled mean spherical approximation is used for the direct correlation function. The three-body effect is found to play a significant role and is incorporated here through a simple parametrization of the corresponding correlation function in a perturbative approach and also alternatively using a suitable version of the nonperturbative modified weighted density approach. The calculated phase diagrams for two different colloidal systems are shown to be in excellent agreement with the corresponding experimental results. © 1995 The American Physical Society.