Experimental study of nonlinear dielectric relaxation spectra of ferroelectric liquid crystals in the smectic c phase
Experimental study of nonlinear dielectric relaxation spectra of ferroelectric liquid crystals in the smectic c phase
复制标题
近晶c相铁电液晶非线性介电弛豫谱的实验研究
DOI：
10.1143/jjap.32.4571
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
R. Hayakawa
中科院分区：
文献类型：
--
作者：
Y. Kimura;R. Hayakawa
研究了两种铁电液晶在手性近晶C（SmC*）相中的非线性介电弛豫谱。线性谱表现为德拜型弛豫，三阶非线性谱也表现为推广到非线性情形的德拜型弛豫。三阶非线性介电增量为负值，表明SmC* 相的FLC介电非线性主要来源于外加电场诱导的分子偶极矩饱和.在整个SmC* 阶段的线性和非线性光谱的配置文件几乎保持不变。在SmA-SmC* 相变温度附近，线性谱表现为Curie-Weiss型的临界行为，三阶谱出现一个尖锐的峰。
Nonlinear dielectric relaxation spectra of two kinds of ferroelectric liquid crystals (FLC) are investigated in the chiral smectic C (SmC*) phase. The linear spectrum shows the relaxation of Debye type and the third-order nonlinear spectrum also shows the relaxation of Debye type generalized to the nonlinear case. The third-order nonlinear dielectric increment is found to be negative, which indicates that the dielectric nonlinearity of FLCs in the SmC* phase mainly originates from the saturation of molecular dipole moments induced by the applied electric field. The profiles of linear and nonlinear spectra remain almost unchanged throughout the SmC* phase. In the vicinity of the SmA-SmC* phase transition temperature, the linear spectrum shows the critical behavior of Curie-Weiss type and the third-order spectrum shows a sharp peak.