ELECTRIC DIPOLES AND PHASE-STABILITY IN NEMATIC LIQUID-CRYSTALS. Vanakaras, A. & Photinos, D. MOLECULAR PHYSICS, 85(6):1089--1104, August, 1995.
ELECTRIC DIPOLES AND PHASE-STABILITY IN NEMATIC LIQUID-CRYSTALS [link]Paper  abstract   bibtex   
A theory for the nematic-isotropic (N-I) phase transition of prolate uniaxial molecules with longitudinal dipole moments is presented. The theory is based on the variational cluster expansion, truncated after the two-molecule term, and is implemented for polar hard spherocylinders with and without attractions, and for polar linear arrays of Lennard-Jones interaction centres. We find that the dipole interactions substantially shift the N-I transition temperature and strongly promote antiparallel molecular association, but have a weak effect on the order parameters, the pressure, and the N-I coexistence densities. The effect of dipoles on phase stability is very sensitive to their position within the molecular frame. Off-centre dipoles are shown to give rise to phase re-entrance according to the sequence N-I-N on heating at constant density. The theory does not predict a stable ferroelectric nematic phase.
@article{vanakaras_electric_1995,
	title = {{ELECTRIC} {DIPOLES} {AND} {PHASE}-{STABILITY} {IN} {NEMATIC} {LIQUID}-{CRYSTALS}},
	volume = {85},
	issn = {0026-8976},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=4&SID=X2d@phhlNdC3Cpddf9B&page=1&doc=24},
	abstract = {A theory for the nematic-isotropic (N-I) phase transition of prolate uniaxial molecules with longitudinal dipole moments is presented. The theory is based on the variational cluster expansion, truncated after the two-molecule term, and is implemented for polar hard spherocylinders with and without attractions, and for polar linear arrays of Lennard-Jones interaction centres. We find that the dipole interactions substantially shift the N-I transition temperature and strongly promote antiparallel molecular association, but have a weak effect on the order parameters, the pressure, and the N-I coexistence densities. The effect of dipoles on phase stability is very sensitive to their position within the molecular frame. Off-centre dipoles are shown to give rise to phase re-entrance according to the sequence N-I-N on heating at constant density. The theory does not predict a stable ferroelectric nematic phase.},
	number = {6},
	urldate = {2009-01-31TZ},
	journal = {MOLECULAR PHYSICS},
	author = {Vanakaras, AG and Photinos, DJ},
	month = aug,
	year = {1995},
	pages = {1089--1104}
}
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