Influences of surface and flexoelectric polarization on the effective anchoring energy in nematic liquid crystal

• Published in: Chinese physics B Vol. 24; no. 10; pp. 349 - 358
• Main Author: 关荣华 叶文江 邢红玉
• Format: Journal Article
• Language: English
• Published: 01.10.2015
• Subjects: Anchoring; Electric potential; Mathematical analysis; Nematic; Polarization; Strength; Surface chemistry; Voltage; 倾斜角度; 向列相液晶; 弱锚定; 挠曲; 电极化; 能量; 表面极化; 解析表达式
• DOI: 10.1088/1674-1056/24/10/106102
• ISSN: 1674-1056

The physical effects on surface and flexoelectric polarization in a weak anchoring nematic liquid crystal cell are investigated systematically. We derive the analytic expressions of two effective anchoring energies for lower and upper substrates respectively as well as their effective anchoring strengths and corresponding tilt angles of effective easy direction.All of these quantities are relevant to the magnitudes of both two polarizations and the applied voltage U. Based on these expressions, the variations of effective anchoring strength and the tilt angle with the applied voltage are calculated for the fixed values of two polarizations. For an original weak anchoring hybrid aligned nematic cell, it may be equivalent to a planar cell for a small value of U and has a threshold voltage. The variation of reduced threshold voltage with reduced surface polarization strength is also calculated. The role of surface polarization is important without the adsorptive ions considered.