MONTE-CARLO STUDY OF DIPOLAR ELLIPSOIDS .2. SEARCH FOR AN ISOTROPIC NEMATIC PHASE-TRANSITION

This new study of the hard ellipsoids system by Monte Carlo simulations invalidates previous simulation work on the localization of the isotropic-nematic phase transition (Molec. Phys., 55, 1171 (1985)). The discrepancies are demonstrated to originate in size effects. Our main result is that the system of hard ellipsoids of elongation 3 has no stable nematic phase, except maybe in a very narrow density domain close to the solid phase. This phase diagram is not modified by central dipolar interactions between the ellipsoids. The disagreement between theoretical predictions and simulation data concerning the localization of the isotropic-nematic transition is therefore larger than previously stated.