Monte Carlo模拟空间各向异性势向列相液晶微滴

计算物理 ›› 2008, Vol. 25 ›› Issue (3): 315-322.

Monte Carlo模拟空间各向异性势向列相液晶微滴

张艳君^1,2,3, 张志东³, 朱礼智⁴

1. 中国科学院长春光学精密机械与物理研究所, 吉林长春 130033;
2. 中国科学院研究生院, 北京 100039;
3. 河北工业大学理学院, 天津 300130;
4. 天津科技大学包装与印刷工程学院, 天津 300222

收稿日期:2006-10-31 修回日期:2007-06-08 出版日期:2008-05-25 发布日期:2008-05-25
作者简介:张艳君(1977-),女,河北邢台,博士生,从事液晶物理及液晶器件物理方面的研究.
基金资助:
河北省高校重点学校资助项目;河北省自然科学基金(103002)资助项目

Monte Carlo Simulation of Nematic Droplets with Spatially Anisotropic Pair Potential

ZHANG Yanjun^1,2,3, ZHANG Zhidong³, Zhu Lizhi⁴

1. Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;
2. Graduate School of the Chinese Academy of Sciences, Beijing, 100039, China;
3. School of Science, Hebei University of Technology, Tianjin 300130, China;
4. Tianjin University of Science & Technology, Tianjin 300222, China

Received:2006-10-31 Revised:2007-06-08 Online:2008-05-25 Published:2008-05-25

摘要/Abstract

摘要： 基于分子两体势,用Monte Carlo方法计算向列相液晶微滴.两体势基于格点模型,是空间各向异性的且依赖于液晶的弹性常数.假定向列相液晶微滴具有自由表面,引入切向内禀强度定量描写表面引发的分子内禀易取向的强弱.通过各向异性势的两种方案,在低温下计算切向内禀强度和二阶序参数在微滴内不同区域的变化,与Lebwohl-Lasher模型作对比分析.结果表明:只有一种方案在微滴表面产生内禀易取向,且内禀强度值的大小与K₃₃/K₁₁值有关;空间不完整的向列相液晶使得微滴由内层到外层有序度越来越低.

关键词: 空间各向异性两体势, MonteCarlo方法, 向列相液晶微滴, 自由表面

Abstract: Nematic droplets are studied with Monte Carlo simulation in a spatially anisotropic molecular pair potential model. The potential is based on a lattice model and dependent on elastic constants of liquid crystals. We assume that nematic droplet surface is a free surface and introduce tangent-introrse intensity to quantitatively describe intrinsic anchoring induced by surface. The tangent-introrse intensity and the second order parameters in different regions of droplets at low temperature are calculated by two schemes with spatially anisotropic potential and are compared with those in Lebwohl-Lasher model. Only one scheme can give intrinsic easy axis near droplets surface and introrse intensity is related to K₃₃/K₁₁. The degree of nematic order in the vicinity of droplet surface becomes lower from inner shell to outer shell due to incomplete anisotropic nematic-nematic interactions.

Key words: spatially anisotropic pair potential, Monte Carlo simulation, nematic droplets, free surface

中图分类号:

O753

张艳君, 张志东, 朱礼智. Monte Carlo模拟空间各向异性势向列相液晶微滴[J]. 计算物理, 2008, 25(3): 315-322.

ZHANG Yanjun, ZHANG Zhidong, Zhu Lizhi. Monte Carlo Simulation of Nematic Droplets with Spatially Anisotropic Pair Potential[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2008, 25(3): 315-322.

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