中国物理B ›› 2016, Vol. 25 ›› Issue (3): 36101-036101.doi: 10.1088/1674-1056/25/3/036101

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Theoretical analysis of the influence of flexoelectric effect on the defect site in nematic inversion walls

Gui-Li Zheng(郑桂丽), Hui Zhang(张辉), Wen-Jiang Ye(叶文江),Zhi-Dong Zhang(张志东), Hong-Wei Song(宋宏伟), Li Xuan(宣丽)   

  1. 1. State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. School of Sciences, Hebei University of Technology, Tianjin 300401, China;
    4. College of Electronic Science and Engineering, Jilin University, Changchun 130021, China
  • 收稿日期:2015-10-11 修回日期:2015-11-28 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Gui-Li Zheng, Zhi-Dong Zhang E-mail:guili0919@163.com;zhidongzhang1961@163.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11374087, 11274088, and 11304074), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2014202123 and A2016202282), the Research Project of Hebei Education Department, China (Grant Nos. QN2014130 and QN2015260), and the Key Subject Construction Project of Hebei Province University, China.

Theoretical analysis of the influence of flexoelectric effect on the defect site in nematic inversion walls

Gui-Li Zheng(郑桂丽)1,2,3, Hui Zhang(张辉)3, Wen-Jiang Ye(叶文江)3,Zhi-Dong Zhang(张志东)3, Hong-Wei Song(宋宏伟)4, Li Xuan(宣丽)1   

  1. 1. State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. School of Sciences, Hebei University of Technology, Tianjin 300401, China;
    4. College of Electronic Science and Engineering, Jilin University, Changchun 130021, China
  • Received:2015-10-11 Revised:2015-11-28 Online:2016-03-05 Published:2016-03-05
  • Contact: Gui-Li Zheng, Zhi-Dong Zhang E-mail:guili0919@163.com;zhidongzhang1961@163.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11374087, 11274088, and 11304074), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2014202123 and A2016202282), the Research Project of Hebei Education Department, China (Grant Nos. QN2014130 and QN2015260), and the Key Subject Construction Project of Hebei Province University, China.

摘要:

Based on the experimental phenomena of flexoelectric response at defect sites in nematic inversion walls conducted by Kumar et al., we gave the theoretical analysis using the Frank elastic theory. When a direct-current electric field normal to the plane of the substrate is applied to the parallel aligned nematic liquid crystal cell with weak anchoring, the rotation of ± 1 defects in the narrow inversion walls can be exhibited. The free energy of liquid crystal molecules around the +1 and-1 defect sites in the nematic inversion walls under the electric field was formulated and the electric-field-driven structural changes at the defect site characterized by polar and azimuthal angles of the local director were simulated. The results reveal that the deviation of azimuthal angle induced by flexoelectric effect are consistent with the switching of extinction brushes at the +1 and-1 defects obtained in the experiment conducted by Kumar et al.

关键词: liquid crystal, flexoelectric effect, ? defects, Frank theory

Abstract:

Based on the experimental phenomena of flexoelectric response at defect sites in nematic inversion walls conducted by Kumar et al., we gave the theoretical analysis using the Frank elastic theory. When a direct-current electric field normal to the plane of the substrate is applied to the parallel aligned nematic liquid crystal cell with weak anchoring, the rotation of ± 1 defects in the narrow inversion walls can be exhibited. The free energy of liquid crystal molecules around the +1 and-1 defect sites in the nematic inversion walls under the electric field was formulated and the electric-field-driven structural changes at the defect site characterized by polar and azimuthal angles of the local director were simulated. The results reveal that the deviation of azimuthal angle induced by flexoelectric effect are consistent with the switching of extinction brushes at the +1 and-1 defects obtained in the experiment conducted by Kumar et al.

Key words: liquid crystal, flexoelectric effect, ? defects, Frank theory

中图分类号:  (Defects in liquid crystals)

  • 61.30.Jf
64.70.mf (Theory and modeling of specific liquid crystal transitions, including computer simulation)