University of Maribor, Faculty of Natural Sciences and Mathematics, Koroska cesta 160, 2000 Maribor, Slovenia.
Beilstein J Org Chem. 2010 Jul 7;6:74. doi: 10.3762/bjoc.6.74.
Orientational ordering of a homogeneous mixture of uniaxial liquid crystalline (LC) molecules and magnetic nanoparticles (NPs) is studied using the Lebwohl-Lasher lattice model. We consider cases where NPs tend to be oriented perpendicularly to LC molecules due to elastic forces. We study domain-type configurations of ensembles, which are quenched from the isotropic phase. We show that for large enough concentrations of NPs the long range uniaxial nematic ordering is replaced by short range order exhibiting strong biaxiality. This suggests that the impact of NPs on orientational ordering of LCs for appropriate concentrations of NPs is reminiscent to the influence of quenched random fields which locally enforce a biaxial ordering.
使用 Lebwohl-Lasher 格子模型研究了单轴液晶（LC）分子和磁性纳米粒子（NPs）均匀混合物的取向有序。我们考虑由于弹性力 NPs 倾向于垂直于 LC 分子取向的情况。我们研究了从各向同性相淬火的集合体的域型配置。我们表明，对于 NP 的浓度足够大的情况，长程单轴向列有序被表现出强烈双轴性的短程有序所取代。这表明，对于适当浓度的 NPs，NPs 对 LC 的取向有序的影响类似于淬火随机场的影响，淬火随机场局部强制产生双轴有序。
