On a Simple Way for Obtaining Important Material Constants of a Nematic Liquid Crystal: Longitudinal Flexoelectric Domains Under the Joint Action of DC and AC Voltages

• Published in: Molecular crystals and liquid crystals (Philadelphia, Pa. : 2003) Vol. 449; no. 1; pp. 33 - 45
• Main Authors: Marinov, Y., Petrov, A. G., Hinov, H. P.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.07.2006
• Subjects: determination; flexoelectric domains; material constants
• ISSN: 1542-1406; 1563-5287
• DOI: 10.1080/15421400600580188

The threshold characteristics U c (U ac ), q c (U ac )andq c (U c ), whereU c is the d.c. threshold voltage, U ac is a high-frequency orienting voltage with a frequency above 5000 Hz, and q c is the threshold wave number of the flexoelectric domains of Vistin'-Pikin-Bobylev, excited under the joint action of a d.c. voltage and a high-frequency orienting voltage, have been theoretically calculated for the case of anisotropic elasticity. These domains have been experimentally obtained in the nematic liquid crystal p-n-butyl-p-methoxyazoxy-benzene (BMAOB). The fitting of the experimental points by the theoretical curves permitted to obtain precisely the elastic constants of splay K 11 and twist , and the modulus of the difference between the flexoelectric coefficients of splay e 1z and bend , for a Δϵ, varying between − 0.20 and − 0.25.