de Oliveira E J L, de Melo D C S, Pereira Maria S S, Evangelista L R, de Oliveira I N
Instituto de Física, Universidade Federal de Alagoas 57072-970 Maceió-AL, Brazil.
Departamento de Física, Universidade Estadual de Maringá 87020-900 Maringá-PR, Brazil.
Phys Rev E. 2020 Aug;102(2-1):022702. doi: 10.1103/PhysRevE.102.022702.
The present study is devoted to the investigation of surface anchoring and finite-size effects on nematic-smectic-A-smectic-C (N-Sm-A-Sm-C) phase transitions in free-standing films. Using an extended version of the molecular theory for smectic-C liquid crystals, we analyze how surface anchoring and film thickness affect the thermal behavior of the order parameters in free-standing smectic films. In particular, we determine how the transition temperature depends on the surface ordering and film thickness. We show that the additional orientational order imposed by the surface anchoring may lead to a stabilization of order parameters in central layers, thus modifying the nature of the phase transitions. We compare our results with experimental findings for typical thermotropic compounds presenting a N-Sm-A-Sm-C phase sequence.
本研究致力于探讨表面锚定和有限尺寸效应对独立薄膜中向列相-近晶A相-近晶C相（N-Sm-A-Sm-C）相变的影响。利用近晶C液晶分子理论的扩展版本，我们分析了表面锚定和薄膜厚度如何影响独立近晶薄膜中序参量的热行为。特别地，我们确定了转变温度如何依赖于表面有序性和薄膜厚度。我们表明，表面锚定施加的额外取向序可能导致中心层序参量的稳定，从而改变相变的性质。我们将我们的结果与呈现N-Sm-A-Sm-C相序列的典型热致化合物的实验结果进行了比较。
