Ferroelectric ordering in chiral smectic-C* liquid crystals determined by nonchiral intermolecular interactions.
Ferroelectric ordering in chiral smectic-C* liquid crystals determined by nonchiral intermolecular interactions.
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由非手性分子间相互作用决定的手性近晶-C*液晶中的铁电排序。
DOI：
10.1103/physreve.77.031701
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
M. Gorkunov
中科院分区：
文献类型：
--
作者：
M. Osipov;M. Gorkunov
本文讨论了手性近晶C ~* 液晶铁电有序化的一般微观机制。结果表明，如果介晶分子具有足够低的对称性，自发极化是成比例的近晶-C相的双轴矢量序参数之一。该序参量可由对分子手性不敏感的分子间相互作用决定。同时，极化也与赝标参数成正比，如果分子是非手性的，则赝标参数为零。铁电有序的一般统计理论是由两个特殊的模型。第一个模型是基于静电四极-四极相互作用，它使人们能够获得明确的自发极化的解析表达式。在第二个模型中，分子的手性和极性由一对偏离中心的非平行偶极子决定。对于这种情况下，自发极化的数值计算作为温度的函数。该理论为包括经典博尔德模型在内的先前方法提供了更一般的解释。
General microscopic mechanism of ferroelectric ordering in chiral smectic-C* liquid crystals is considered. It is shown that if the mesogenic molecules have a sufficiently low symmetry, the spontaneous polarization is proportional to one of the biaxial vector order parameters of the smectic-C phase. This order parameter may be determined by intermolecular interactions which are not sensitive to molecular chirality. At the same time, the polarization is also proportional to a pseudoscalar parameter which vanishes if the molecules are nonchiral. The general statistical theory of ferroelectric ordering is illustrated by two particular models. The first model is based on electrostatic quadrupole-quadrupole interactions, and it enables one to obtain explicit analytical expressions for the spontaneous polarization. In the second model, the molecular chirality and polarity are determined by a pair of off-center nonparallel dipoles. For this case, the spontaneous polarization is calculated numerically as a function of temperature. The theory provides a more general interpretation of the previous approaches including the classical Boulder model.
DOI：
10.1103/physreve.75.060701
发表时间：
2007-01
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
M. Gorkunov;F. Giesselmann;J. Lagerwall;T. Sluckin;M. Osipov
通讯作者：
M. Gorkunov;F. Giesselmann;J. Lagerwall;T. Sluckin;M. Osipov