EVALUATION OF STRUCTURE AND OPTICAL PROPERTIES OF LB ULTRATHIN FILMS USING THE ATTENUATED TOTAL REFLECTION MEASUREMENT

本文采用衰减全反射（ATR）测量方法对LB超薄膜的结构和光学性能进行了评价。我们已经研究了各种LB膜的ATR性能。用ATR法研究了吸附和不吸附电子给体的四氰喹诺二甲烷LB膜的结构。通过将正交ATR曲线与实验曲线拟合，确定了单轴各向异性介质SQ LB膜的复介电常数。考察了螺吡喃（SP） LB膜在不同摩尔比下的ATR性能。含有十八烷的SP LB膜具有高阶结构，并且由于光异构化而表现出可逆的变化。吸附菁染料的偶氮苯LB膜的ATR性能与热处理后的激光波长有关，复介电常数实部随波长变短而减小。这种特性被认为是由于强吸收引起的反常色散。在聚酰亚胺LB对准层液晶电池的ATR测量中，观察到表面等离子体波模式和导波模式的共振激发。液晶分子的倾斜角度，5CB，在电池中已经评估从测量。利用ATR法对花生镉盐LB膜的表面粗糙度进行了估计。这些结果对LB薄膜的光学应用具有重要意义。

In this report, structure and optical properties of LB ultrathin films have been evaluated using the attenuated total reflection (ATR) measurement. We have already investigated the ATR properties of various LB films.The structure of the tetracyanoquinodimethane LB films with and without adsorbed electronic donors was investigated using the ATR method. The complex dielectric constants of the squarylium (SQ) LB film of uniaxial anisotrpic dielectrics were determined by fitting the throretical ATR curves to the experimental ones. The ATR prorerties of the spiropyran (SP) LB films were obse ved for various molar ratios of the mixtures of SP,arachidic acid and octadecane. The SP LB films containing the octadecane had the higher order structure and exhibited the reversible changes due to the photoisomerization. the ATR properties of the azobenzene LB films adsorbing cyanine dyes depended upon the wavelength of the lasers after heat treatments, and the real parts of the complex dielectric constants decreased as the wavelength become shorter. The properties were thought to be due to an anomalous dispersion caused by strong absorption. The resonant excitaions of the surface plasmon wave mode and the guided wave ones were observed in the ATR measurements for the liquid crystal cell with the polyimide LB aligning layrs. Tilt angles of the liquid crystal molecules, 5CB,in the cell have been evaluated from the messurements. The surface roughness of the arachidic cadmium salt LB film was estimated using the excited surface plasmon in the ATR method. These results are very useful for optical applications of the LB films.