Fundamental Study on Electroclinic Effect in Smectic A Liquid Crystals and the Application for Fast Optical Modulator

近晶A液晶电致效应的基础研究及快速光调制器的应用

基本信息

批准号：
63550227
负责人：
TAKEZOE Hideo
金额：
$ 1.28万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550227/
关键词：
ferroelectric liquid crystal electroclinic effect smectic A phase electro optic effect X-ray diffraction layer structure X線回折 X線線回折

项目摘要

In the first year of this project, we obtained the results that not only the molecular tilt but also the layer deformation are induced in the electroclinic effect.1. Using the cells whose layers are perpendicular to the glass surfaces, the X-ray diffraction experiments were carried out. The X-ray diffraction intensity was measured under an electric field as rotating the cell with the detector fixed at the Bragg angle of the inter layer spacing. With increasing the field, two peaks appeared at the symmetry positions and the separation became wide. This fact suggests that the chevron layer structure is formed by applying the field. It was confirmed that the layer tilt angle is nearly equal to the molecular tilt angle in the low field region.2. The above experiment gives information about the layer deformation perpendicular to the glass surfaces. The microscope observation, however, suggests the existence of the layer deformation parallel to the surfaces. To confirm this, it is necessary to observe the transmission Laue pattern. For this purpose, we are trying to detect the Laue pattern using the cells composed with very thin glasses. At this moment, the diffuse scattering due to the glasses prevents the observation of the Laue spot.3. Since the electroclinic effect is equivalent to the excitation of the soft mode in the paraelectric phase, we should observe the divergent increase of the dielectric constant as the temperature approaches to the phase transition point. We developed the automatic system for determining dielectric constant and confirmed the behavior.

在该项目的第一年，我们获得了电斜效应不仅引起分子倾斜而且引起层变形的结果。 1．使用层与玻璃表面垂直的单元进行X射线衍射实验。 X射线衍射强度是在电场下测量的，同时旋转池，检测器固定在层间距的布拉格角处。随着电场的增加，对称位置出现两个峰，并且间距变宽。这一事实表明 V 形层结构是通过施加场形成的。证实低场区层倾斜角与分子倾斜角几乎相等。 2．上述实验提供了有关垂直于玻璃表面的层变形的信息。然而，显微镜观察表明存在平行于表面的层变形。为了证实这一点，有必要观察传输劳厄模式。为此，我们正在尝试使用由非常薄的玻璃组成的细胞来检测劳厄图案。此时，由于眼镜的漫散射，妨碍了劳厄斑的观察。 3．由于电斜效应相当于顺电相中软模的激发，因此我们应该观察到随着温度接近相变点介电常数的发散性增加。我们开发了用于确定介电常数的自动系统并确认了其行为。