Size effect and stability of polarized fluid phases

The existence of a ferroelectric fluid phase for systems of 1000-2000 dipolar hard or soft spheres is well established by numerical simulations. Theoretical approaches proposed to determine the stability of such a phase are either in qualitative agreement with the simulation results or disagree with them. Experimental results for systems of molecules or particles with large electric or magnetic dipole moments are also inconclusive. As a contribution to the question of existence and stability of a fluid ferroelectric phase this simulation work considers system sizes of the order of 10 000 particles, thus an order of magnitude larger than those used in previous studies. It shows that although ferroelectricity is not affected by an increase of system size, different spatial arrangements of the dipolar hard spheres in such a phase are possible whose free energies seem to differ only marginally.