Brown C V, Mottram N J
Physics and Mathematical Sciences, The Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Sep;68(3 Pt 1):031702. doi: 10.1103/PhysRevE.68.031702. Epub 2003 Sep 5.
Continuum theory is used to demonstrate that the presence of flexoelectricity significantly alters the response to an applied voltage of a homogeneous nematic liquid crystal cell above the ac Fréedericksz threshold voltage. In such a system there is a fitting degeneracy: we obtain very good fits between theory and experimental permittivity data using any value of the sum of flexoelectric coefficients, e(11)+e(33), between 0.0 C/m and 1.5 x 10(-11) C/m. The corresponding values of the nematic bend elastic constant show an inverse parabolic relationship with e(11)+e(33), with K33 being reduced down to 90% of its value when flexoelectricity is neglected.
连续统理论被用于证明，在交流弗雷德里克斯阈值电压之上，挠曲电效应的存在会显著改变均匀向列型液晶盒对施加电压的响应。在这样一个系统中存在拟合简并性：使用介于0.0 C/m至1.5×10⁻¹¹ C/m之间的任何挠曲电系数之和e(11)+e(33)的值，我们都能在理论与实验介电常数数据之间获得非常好的拟合。向列型弯曲弹性常数的相应值与e(11)+e(33)呈现反抛物线关系，当忽略挠曲电效应时，K33降低至其值的90%。
