Phase diagram of a lattice microemulsion model in two dimensions.

The phase diagram of a lattice microemulsion model proposed by Ciach, Høye and Stell [1,2] is studied using mean-field theory and Monte Carlo simulations. Surfactant directional degrees of freedom are summed out exactly before mean-field theory is applied, and the resulting phase diagrams are much improved compared with previous mean-field results. The critical line and tricritical point is located using Monte Carlo simulations and finite size scaling.