Elastic Constants of Nematic Liquid Crystals
Elastic Constants of Nematic Liquid Crystals
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向列液晶的弹性常数
DOI：
10.1515/zna-1972-0613
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发表时间：
1972
期刊：
影响因子：
--
通讯作者：
G. Meier
中科院分区：
文献类型：
--
作者：
H. Gruler;T. Scheffer;G. Meier
本文给出了向列相液晶在外加电场或磁场时发生形变的理论处理和实验观察。我们只考虑向列相材料中的法向变形，其中流体流动和其他动态现象不起作用。在磁场中考虑了三种重要的样品几何形状，实验观察到的变形与理论符合得很好。从器件的观点来看，电场引起的法向形变是有意义的，我们给出了一种即使对于大的介电各向异性也是有效的解。这一解决方案已经得到了实验验证。我们对电场和磁场产生的变形进行了详细的比较，结果表明，即使电场是不均匀的，变形的形式也是相似的。作为观察变形的一种手段，讨论了双折射和电容随变形的变化。
Abstract We present a theoretical treatment and give experimental observations of the deformation that occurs in a nematic liquid crystal when electric or magnetic fields are applied. We consider only normal deformations in the nematic material where fluid flow and other dynamic phenomena play no role. Three important sample geometries are considered in the magnetic field, and the experimentally observed deformations are in good agreement with theory. The normal deformation induced by electric fields is of interest from a device standpoint, and we give a solution for the deformation that is valid even for large dielectric anisotropics. This solution has been experimentally verified. We give a detailed comparison of the distortions produced by electric and magnetic fields and show that the deformations are of a similar form even though the field is nonuniform in the electric case. The change in birefringence and electrical capacitance as a function of distortion is discussed as a means of observing the deformation.