In Situ Optical Characterization of Twinning in Liquid Crystalline Blue Phases
In Situ Optical Characterization of Twinning in Liquid Crystalline Blue Phases
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液晶蓝相孪晶的原位光学表征
DOI：
10.1021/acsami.1c06873
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发表时间：
2021
影响因子：
9.5
通讯作者：
Ozaki Masanori
中科院分区：
文献类型：
--
作者：
Zhang Yuxian;Yoshida Hiroyuki;Cho SeongYong;Fukuda Jun-ichi;Ozaki Masanori
晶体孪晶是两个或多个相同种类的单晶在它们的取向上具有特定的晶体学关系的共生。在这里，我们进行微观光学表征（211）双胞胎在三维液晶相称为蓝相（BP），与I4132空间群对称性。我们描述的效果上的光学衍射图案Kossel图案的蓝相和分析的图案，推导出的结构信息，如孪生元素和以前未注意到的偏差，从完美的立方结构在零电场。此外，我们获得了现场观察作为一个字段是沿着[110]方向的孪生晶体，并发现孪晶界显示出钉扎效应，定义的取向的孪晶对通过正交结构变换。我们的研究结果不仅为BPs作为电光晶体的应用提供了重要的见解，而且也为理解晶体学的分级结构迈出了一步。
Crystal twinning is an intergrowth of two or more single crystals of the same species with specific crystallographic relations in their orientations. Here, we perform microscopic optical characterization of (211) twins in the three-dimensional liquid crystalline phase known as the blue phase (BP), with I4132 space group symmetry. We describe the effect of twinning on the optical diffraction pattern—Kossel pattern—of blue phases and analyze the patterns to deduce structural information such as the twin elements and the previously unnoticed deviations from the perfect cubic structure at zero electric field. Further, we obtain in situ observations as a field is applied along the [110] direction of the twinning crystals and find that the twin boundary shows a pinning effect that defines the orientation of the twinned pair through the cubic-to-orthogonal structure transformation. Our findings not only provide important insights for the application of BPs as electro-optic crystals but also present a step in understanding the hierarchical structures that are crystallographic.