Abstract
The deformations of homeotropic nematic layers induced by ac electric field of frequency f were studied numerically. Two kinds of nematic liquid crystals with small negative dielectric anisotropy, De < 0, were considered: (i) the non-flexoelectric nematic, (ii) the nematic characterised by the positive sum of flexoelectric coefficients e = e11 + e33 > 0. It was found that at sufficiently low frequencies, the deformations varied with time. The deformations of purely dielectric nature had the period 1/(2f). The time period of flexoelectric distortions was equal to 1/f. The influence of rotational viscosity and of thickness of the layer on the dynamics of deformations was analysed.
References
Blinov L.M., Chigrinov V.G., Electro-optic Effects in Liquid Crystal Materials, Springer Verlag, New York, 1993.
Deuling H.J., “Elasticity of nematic liquid crystals”, in: Liquid Crystals, Solid State Physics, Suppl. 14, pp. 103-107, edited by E. Liebert, Academic Press, New York, 1978.
Derfel G., Buczkowska M., Opto-Electron. Rev., 19 (2011) 53.
Gruler H., Cheung L., J. Appl. Phys., 46 (1975) 5097.
Derzhanski A.I., Petrov A.G., Acta Phys. Pol., A55 (1979) 747.