(139e) Like-Charge Attraction Of Spheres - Global Phase Diagram And Critical Scaling

We calculate the full phase diagram of spherical charged colloidal particles using Monte Carlo free energy calculations. The system is described using the primitive model, consisting of explicit hard-sphere colloids and point counterions in a uniform dielectric continuum. We show that at colloid charges Q >= 20 times the counterion charge, the gas-liquid critical point is metastable with respect to broad gas-solid phase separation. Approximate free energy calculations with only one and four particles in the fluid and solid phases, respectively, are used to determine the critical line below which a broad gas-solid phase separation occurs for highly charged colloids up to Q = 2000. We propose the scaling law T_c = Q^1/2 for this critical temperature.