Pattern formation of chevrons in the conduction regime in homeotropically aligned liquid crystals
Pattern formation of chevrons in the conduction regime in homeotropically aligned liquid crystals
复制标题
垂直排列液晶中传导区 V 形图案的形成
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
S. Kai
中科院分区：
文献类型：
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作者：
Jong;Y. Hidaka;A. Rossberg;S. Kai
我们报道的是人字形~人字形图案！在具有高电导率的同向排列的液晶中观察到。我们把注意力集中在传导区域中观察到的两种类型的人字形上。得到了阈值电压和人字形波带的双周期特性，即条纹波的短波长L 1和人字形波段的长波长L 2！利用交叉偏振片装置，我们还测定了我们的波长为L的人字形电子束的指向矢场，它表现出周期性的面内旋转。随着电压的升高，我们得到了本质上不同的分叉序列，从而得到了人字形的类型。L 2的频率依赖关系也表现出与这两种人字形的性质不同的行为。根据最新的理论研究对实验结果进行了讨论。
We report on chevrons ~herringbonelike patterns! observed in homeotropically aligned liquid crystals with high electric conductivity. We focus our attention on two types of chevrons observed in the conduction regime. The threshold voltage and the characteristic double periodicity of chevrons ~i.e., the short wavelength l 1 of the striated rolls and the long wavelength l 2 of the chevron bands! have been measured as functions of the applied electric frequency f. With the aid of a crossed polarizer set, we have, in addition, determined the director field which shows a periodic in-plane rotation for our chevrons ~with a wavelength l 2). We arrived at the types of chevrons after qualitatively different bifurcation sequences with increasing voltage. The frequency dependence of l 2 also shows a qualitatively different behavior with respect to the two types of chevrons. The experimental results are discussed in terms of recent theoretical investigations.