Evidence of anisotropic quenched disorder effects on a smectic liquid crystal confined in porous silicon.
Evidence of anisotropic quenched disorder effects on a smectic liquid crystal confined in porous silicon.
复制标题
各向异性淬火无序对限制在多孔硅中的近晶液晶的影响的证据。
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
M. Guendouz
中科院分区：
文献类型：
--
作者：
R. Guégan;D. Morineau;C. Loverdo;W. Béziel;M. Guendouz
用中子散射方法分析了近晶液晶辛基氰基联苯(8CB)在多孔硅薄膜(PS)一维纳米孔中的结构。近晶转变被完全抑制，导致沿孔轴排列的短程有序近晶相的延伸。它在一个扩展的温度范围内可逆地演化，在纯8CB中低于N-SMA相变的50K。这一行为与以前在不同的一维多孔材料中观察到的近晶有很大的不同。这种惊人行为的连贯图景需要调用猝灭的无序效应。多孔硅内表面的强烈无序性质表现为与近晶有序相耦合的无序场。PS纳米通道的一维特性为研究猝灭无序效应提供了新的视角，到目前为止，对PS纳米通道的观察仅限于均匀的随机多孔材料。
We present a neutron scattering analysis of the structure of the smectic liquid crystal octylcyanobiphenyl (8CB) confined in one-dimensional nanopores of porous silicon films (PS). The smectic transition is completely suppressed, leading to the extension of a short-range ordered smectic phase aligned along the pore axis. It evolves reversibly over an extended temperature range, down to 50 K below the N-SmA transition in pure 8CB. This behavior strongly differs from previous observations of smectics in different one-dimensional porous materials. A coherent picture of this striking behavior requires that quenched disorder effects are invoked. The strongly disordered nature of the inner surface of PS acts as random fields coupling to the smectic order. The one-dimensionality of PS nanochannels offers perspectives on quenched disorder effects, of which observation has been restricted to homogeneous random porous materials so far.