The realization of a spontaneous macroscopic ferroelectric order in fluids ofanisotropic mesogens is a topic of both fundamental and technological interest.Recently, we demonstrated that a system of dipolar achiral disklike ellipsoidscan exhibit long-searched ferroelectric liquid crystalline phases of dipolarorigin. In the present work, extensive off-lattice Monte Carlo simulations areused to investigate the phase behavior of the system under the influences ofthe electrostatic boundary conditions that restrict any global polarization. Wefind that the system develops strongly ferroelectric slablike domainsperiodically arranged in an antiferroelectric fashion. Exploring the phasebehavior at different dipole strengths, we find existence of the ferroelectricnematic and ferroelectric columnar order inside the domains. For higher dipolestrengths, a biaxial phase is also obtained with a similar periodic array offerroelectric slabs of antiparallel polarizations. We have studied thedepolarizing effects by using both the Ewald summation and the sphericalcut-off techniques. We present and compare the results of the two differentapproaches of considering the depolarizing effects in this anisotropic system.It is explicitly shown that the domain size increases with the system size as aresult of considering longer range of dipolar interactions. The system exhibitspronounced system size effects for stronger dipolar interactions. The resultsprovide strong evidence to the novel understanding that the dipolarinteractions are indeed sufficient to produce long range ferroelectric order inanisotropic fluids.
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