论文标题
观察单轴铁电晶状体A期
Observation of a uniaxial ferroelectric smectic A phase
论文作者
论文摘要
我们报告了铁电列领域的新型液晶阶段近晶$ a_f $。近元$ a_f $是小极性，杆状分子的相位，形成二维流体层，大约是平均分子长度。该阶段是单轴的，分子主管是局部平均长轴取向，正常与层平面，而铁电的正常，并具有与导演平行的自发电化极化。极化测量表明$ \ sim 10 $ debye纵向分子偶极子几乎完整的极性顺序，并且观察到滞后偏光逆转，其强制性磁场约为$ 2 \ times 10^5 $ v/m。 The smectic $A_F$ phase appears upon cooling in two binary mixtures of partially fluorinated mesogens: 2N/DIO, exhibiting a nematic ($N$) -- smectic $Z_A$ (Sm$Z_A$) -- ferroelectric nematic ($N_F$) -- smectic $A_F$ (Sm$A_F$) phase sequence;和7n/dio，展示$ n $ - sm $ z_a $ - sm $ a_f $ phase序列。后者为研究两个具有正交层的近晶阶段之间的过渡提供了一个机会。
We report the smectic $A_F$, a new liquid crystal phase of the ferroelectric nematic realm. The smectic $A_F$ is a phase of small polar, rod-shaped molecules which form two-dimensional fluid layers spaced by approximately the mean molecular length. The phase is uniaxial, with the molecular director, the local average long-axis orientation, normal to the layer planes, and ferroelectric, with a spontaneous electric polarization parallel to the director. Polarization measurements indicate almost complete polar ordering of the $\sim 10$ Debye longitudinal molecular dipoles, and hysteretic polarization reversal with a coercive field of about $2 \times 10^5$ V/m is observed. The smectic $A_F$ phase appears upon cooling in two binary mixtures of partially fluorinated mesogens: 2N/DIO, exhibiting a nematic ($N$) -- smectic $Z_A$ (Sm$Z_A$) -- ferroelectric nematic ($N_F$) -- smectic $A_F$ (Sm$A_F$) phase sequence; and 7N/DIO, exhibiting an $N$ -- Sm$Z_A$ -- Sm$A_F$ phase sequence. The latter presents an opportunity to study a transition between two smectic phases having orthogonal systems of layers.
