Investigations of orientational order for an antiferroelectric liquid crystal by polarized Raman scattering measurements.
Investigations of orientational order for an antiferroelectric liquid crystal by polarized Raman scattering measurements.
复制标题
通过偏振拉曼散射测量研究反铁电液晶的取向顺序。
DOI：
10.1103/physreve.63.021706
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
T. Kato
中科院分区：
文献类型：
--
作者：
N. Hayashi;T. Kato
用偏振拉曼散射法研究了反铁电液晶分子4-（1-甲基庚氧基羰基）苯基-4（'）-辛氧基联苯-4-羧酸酯在连续近晶相系列中的取向有序。推导了偏振拉曼强度与入射激光偏振态和取向序参量的关系式。即使在手性近晶相中，也可以通过对近晶层结构和光学扰动的适当校正来定义一些表观取向序参数。随着温度的降低，取向序参数发生了不寻常的变化。结果表明，有序参数的不规则变化源于分子取向分布的双轴性，这是由于分子绕其长轴旋转受阻造成的.
The orientational ordering of the antiferroelectric liquid crystal molecules, 4-(1-methyl-heptyloxycarbonyl)phenyl 4(')-octyloxybiphenyl-4-carboxylate was investigated in the series of the successive smectic phases by means of polarized Raman scattering measurement without any external field. An improved equation for the analysis of the polarized Raman intensity was derived as a function of an incident laser polarization and the orientational order parameters. Even in the chiral smectic phases, some apparent orientational order parameters could be defined by the proper corrections for the smectic layer structure and an optical disturbance. An unusual change of the orientational order parameters was observed with decrease in temperature. It was concluded that the irregular variation of the order parameter stemmed from the biaxiality of the molecular orientational distribution, which was attributed to the hindrance of molecular rotation around its long axis.