Electroclinic effect in a chiral paranematic liquid-crystal layer above the bulk nematic-to-isotropic transition temperature
Electroclinic effect in a chiral paranematic liquid-crystal layer above the bulk nematic-to-isotropic transition temperature
复制标题
手性副相液晶层中高于体向列向各向同性转变温度的电致效应
DOI：
10.1103/physreve.93.022701
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发表时间：
2016
影响因子：
2.4
通讯作者：
Rosenblatt, Charles
中科院分区：
文献类型：
--
作者：
Nemitz, Ian R.;Lacaze, Emmanuelle;Rosenblatt, Charles
报道了两种手性液晶在体相手性各向同性-非对称相变温度以上的电斜位测量结果。研究发现，外加电场在极薄的平行四边形层中引起指向矢的旋转θ[θ E]，这种旋转是由电池的两个平面对准衬底引起的。接近转变温度的电斜系数的大小与体手性介电常数的大小以及体各向同性到手性近晶相上方的寄生区的大小相当。然而，在paranematic层随温度的变化慢得多，比在paranematic阶段，其弛豫时间是慢了三个以上的数量级比散装手征的电斜效应。
Electroclinic measurements are reported for two chiral liquid crystals above their bulk chiral isotropic–nematic phase transition temperatures. It is found that an applied electric fieldinduces a rotationθ[∝Ε] of the director in the very thin paranematic layers that are induced by the cell's two planar-aligning substrates. The magnitude of the electroclinic coefficientclose to the transition temperature is comparable to that of a bulk chiral nematic, as well as to that of a parasmectic region above a bulk isotropic-to-chiral smectic-phase. However,in the paranematic layer varies much more slowly with temperature than in the parasmectic phase, and its relaxation time is slower by more than three orders of magnitude than that of the bulk chiral nematic electroclinic effect.