DEVELOPMENT OF A SYSTEM FOR CHARACTERIZATION OF LINEAR AND NONLINEAR DIELECTRIC PROPERTY OF NANOMETRIC ORGANIC THIN FILM

本研究的目的是开发一种用于表征有机单层膜的线性和非线性介电特性的测量系统，并测量水表面上单层膜的麦克斯韦位移电流（MDC）和二次谐波产生（SHG）。进一步分析基于硬核单分子膜模型的单分子膜。因此，这项研究已经进行的麦克斯韦位移电流测量的研究人员提出的想法的基础上。研究人员使用棒状极性分子模型分析了有机单层膜的分子运动，假设分子的运动受玻尔兹曼统计的支配。他们从理论上推导出了单分子膜的介电弛豫时间，并分析了手性和非手性单分子膜的MDC生成。他们还分析了单分子膜的相变，并使用连续介质理论解释了混合单分子膜的手性相分离。取向序参数之间的关系，即，获得了分子的1、2、3取向级参数，以及MDC和SHG信号。他们还测量了5CB液晶单层的MDC和SHG。基于连续介质理论分析了偶氮苯构象变化引发的液晶取向转变过程和偶氮苯分子在混合单分子膜体系中的运动，并基于光学透过率和电容的同时测量讨论了液晶的运动.

The purpose of this investigation was to develop a measurement system used for the characterization of linear and nonlinear dielectric properties of organic monolayer films, and to measure Maxwell-displacement current (MDC) and Second Harmonics Generation (SHG) from monolayers on a water surface. Further to analyze monolayers based on a hardcore monolayer model was the purpose. Thus, this investigation has been carried out on the basis of the idea of Maxwell-displacement current measurement proposed by the investigators. The investigators analyzed the molecular motion of organic monolayer films using a rod-like polar molecular model, assuming the motion of molecules is ruled by the Boltzmann statistics. They theoretically derived dielectric relaxation time of monolayers and also analyzed the generation of MDC from chiral and achiral monolayers. They also analyzed the phase transition of monolayers and explained the chiral phase separation of mixed monolayers using a continuum theory. The relationship between the orientational order parameters, i.e., 1st 2nd and 3rd orientational order parameters, and the MDC and SHG signals were obtained. They also measured the MDC and SHG from 5CB liquid crystal monolayers. Further orientational transition process of LCs triggered by conformational change of azobenzene and the molecular motion of azobenzenes in mixed monolayer systems were analyzed based on a continuum theory, and the motion of LCs was discussed based on the simultaneous measurement of optical transmittance and the capacitanace.