Determining the sum of flexoelectric coefficients in nematic liquid crystals by the capacitance method  

作　　者：叶文江 邢红玉 崔文静 周璇 孙玉宝 张志东 

机构地区：[1]School of Sciences, Hebei University of Technology [2]School of Physics, Nankai University

出　　处：《Chinese Physics B》2014年第11期414-421,共8页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11274088,11374087,and 11304074);the Natural Science Foundation of Hebei Province,China(Grant No.A2014202123);the Research Project of Hebei Education Department,China(Grant Nos.Z2012061 and QN2014130);the Science and Technology Plan Project of Hebei Province,China(Grant No.134576260);the Key Subject Construction Project of Hebei Province University,China

摘　　要：A detailed theoretical analysis of determining the sum of flexoelectric coefficients in nematic liquid crystals using the capacitance method is given. In the strong anchoring parallel aligned nematic （PAN） and hybrid aligned nematic （HAN） cells, the dependences of the capacitance on the sum of flexoelectric coefficients and the applied voltage are obtained by numerical simulations, and the distributions of the director and the electric potential for different applied voltages and flexoelectric coefficients are also given. Based on this theoretical analysis, we propose an experimental design for measuring the capacitance of a liquid crystal cell using the improved precision LCR meter E4980A （Agilent）. Through comparing the experimental data with the simulated results, the sum of flexoeletric coefficients can be determined.A detailed theoretical analysis of determining the sum of flexoelectric coefficients in nematic liquid crystals using the capacitance method is given. In the strong anchoring parallel aligned nematic （PAN） and hybrid aligned nematic （HAN） cells, the dependences of the capacitance on the sum of flexoelectric coefficients and the applied voltage are obtained by numerical simulations, and the distributions of the director and the electric potential for different applied voltages and flexoelectric coefficients are also given. Based on this theoretical analysis, we propose an experimental design for measuring the capacitance of a liquid crystal cell using the improved precision LCR meter E4980A （Agilent）. Through comparing the experimental data with the simulated results, the sum of flexoeletric coefficients can be determined.

关 键 词：FLEXOELECTRICITY CAPACITANCE parallel aligned nematic and hybrid aligned nematic liquid crystals 

分 类 号：O753.2[理学—晶体学] TE622.5[石油与天然气工程—油气加工工程]