Stability of ferroelectric fluid and solid phases in the Stockmayer model

Mimimizing a free-energy functional, we investigate the stability of ferroelectric fluid and various solid phases in the Stockmayer system. Our functional is based on the correlations of the isotropic fluid, calculated by integral equations. At the reduced dipole moment m * = 2.0 we found a ferroelectric fluid, but this phase is surpassed by a polarized body-centered tetragonal crystal. Moreover, the system seems to have no liquid phase at all. This behaviour changes when the strength of the isotropic attraction is increased.