Electrooptic and Dielectric Properties in Bent-Shaped Liquid Crystals
Electrooptic and Dielectric Properties in Bent-Shaped Liquid Crystals
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弯曲形液晶的电光和介电特性
DOI：
10.1143/jjap.39.3536
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发表时间：
2000
影响因子：
1.5
通讯作者：
H. Takezoe
中科院分区：
文献类型：
--
作者：
M. Zennyoji;Y. Takanishi;K. Ishikawa;J. Thisayukta;J. Watanabe;H. Takezoe
研究了弯曲液晶分子在反铁电相B2中的电光和介电性质。通过适当选择特定的电场波形，我们成功地选择性地获得了手性相反的层部分混合的均匀手性域、外消旋域和中间域。在三角波场作用下，各域均观察到三稳态开关。矩形波场下的开关电流分布表明，均匀手性结构域的开关时间比外消旋结构域的开关时间慢。自发极化的大小不取决于温度，而取决于分子末端链的碳数。在介电测量中检测到两种弛豫模式，其中一种弛豫模式归因于反铁电有序的畸变。
Electrooptic and dielectric properties were studied in the antiferroelectric phase, B2, of bent-shaped liquid crystal molecules. We have succeeded in selectively obtaining the homogeneously chiral domain, the racemic domain, and the intermediate domain in which layers with opposite chirality are partially mixed, by properly choosing particular waveforms of the electric field applied. Tristable switching was observed for all domains under a triangular wave field. The switching current profiles under a rectangular wave field indicate that the switching time of homogeneously chiral domains is slower than that of racemic domains. The magnitude of spontaneous polarization depends not on temperature but on the carbon number of the terminal chain of the molecules. Two relaxation modes were detected in dielectric measurements, one of which was attributed to the distortion of the antiferroelectric ordering.