Thermotropic biaxial nematic liquid crystals

被引：542

作者：

Madsen, LA

Dingemans, TJ

Nakata, M

Samulski, ET

机构：

[1] Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA

[2] Delft Univ Technol, Fundamentals Adv Mat Grp, NL-2629 HS Delft, Netherlands

[3] Dept Organ & Polymer Mat, Tokyo 1528552, Japan

来源：

PHYSICAL REVIEW LETTERS | 2004年 / 92卷 / 14期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1103/PhysRevLett.92.145505

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We have synthesized liquid crystal (LC) mesogens based on a nonlinear oxadiazole unit that exhibit nematic phases near 200 degreesC. Polarized microscopy and conoscopy indicate that these LCs are biaxial nematics. Unambiguous and quantitative evidence for biaxiality is achieved using H-2 NMR spectroscopy. "2D powder" spectra, obtained by rotating H-2-labeled samples about an axis perpendicular to the magnetic field at similar to200 Hz, yield phase biaxiality parameters of similar to0.1 when coupled with rigorous and proven simulations.

引用

收藏

页码：145505 / 1

页数：4

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