Blinov Lev M, Barnik Mikhail I, Bustamante E Soto, Pelzl Gerhard, Weissflog Wolfgang
Institute of Crystallography, Russian Academy of Science, Leninsky prosp.59, Moscow, 117333, Russia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Feb;67(2 Pt 1):021706. doi: 10.1103/PhysRevE.67.021706. Epub 2003 Feb 26.
A detailed study of the dynamics of electro-optical response has been carried out over the whole temperature range of the antiferroelectric B2 phase of a compound with bent-core shape molecules, a homolog (n=14) of the series 4-chloro-1,3-phenylene bis[4-(4-n-alkylphenylimino)benzoates]. Two types of stripe domains were observed with opposite handedness and simultaneous clock and anticlock motion of the director in the neighboring domains. The temperature dependence of the interlayer potential has been found from the threshold of the transition from the ground antiferroelectric (AF) state to the field-induced ferroelectric (F) state. The rotational viscosity gamma(phi) has been calculated from the dynamics of the field-induced azimuthal director switching between F-F and AF-F states and free relaxation of the director from F to AF state. The electro-optical response was also observed below the AF-F threshold. The latter was attributed to the soft-mode distortion of the molecular tilt angle in the vicinity of the transition from the B2 phase to the isotropic phase.
对一种具有弯曲核形状分子的化合物（4-氯-1,3-亚苯基双[4-(4-正烷基苯基亚氨基)苯甲酸酯]系列的同系物（n = 14））反铁电B2相的整个温度范围内的电光响应动力学进行了详细研究。观察到两种具有相反手性的条纹畴，并且在相邻畴中指向矢同时进行顺时针和逆时针运动。从基态反铁电（AF）态到场致铁电（F）态转变的阈值确定了层间电势的温度依赖性。根据场致方位角指向矢在F-F和AF-F态之间切换的动力学以及指向矢从F态到AF态的自由弛豫计算了旋转粘度γ(φ)。在AF-F阈值以下也观察到了电光响应。后者归因于从B2相到各向同性相转变附近分子倾斜角的软模畸变。
