[1]翟雪雅,刘红.由弹性键连接的V形分子双轴向列相液晶的相变[J].南京师大学报(自然科学版),2010,33(02):31-37.
　Zhai Xueya,Liu Hong.Biaxial Nematic Liquid Crystal Phase Transition of V-Shaped Molecules Connected by Flexible Chain[J].Journal of Nanjing Normal University(Natural Science Edition),2010,33(02):31-37.
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由弹性键连接的V形分子双轴向列相液晶的相变()
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《南京师大学报（自然科学版）》[ISSN:1001-4616/CN:32-1239/N]

卷:
第33卷
期数:
2010年02期
页码:
31-37
栏目:
物理学
出版日期:
2010-06-20

文章信息/Info

Title:
Biaxial Nematic Liquid Crystal Phase Transition of V-Shaped Molecules Connected by Flexible Chain
作者:
翟雪雅;刘红;
南京师范大学物理科学与技术学院, 江苏南京210097
Author(s):
Zhai Xueya; Liu Hong
School of Physics and Technology,Nanjing Normal University,Nanjing 210097,China
关键词:
双轴向列相液晶;  相变;  弯曲核液晶
Keywords:
b iax ia l nem a tics;  phase transition;  bent co re liqu id cry sta l
分类号:
O753.2
摘要:
对由弹性键相连的V形液晶分子系统的相变进行了研究.根据分子间简单相互作用能,利用平均场理论得到系统平衡态序参数随温度的变化,以及系统在分子结构和温度平面内的相图.结果表明液晶相变温度与弹性键强度系数k及棒长比r有关.当k>0和k<0且|k|<r时,随温度的降低,系统从各向同性相经一级相变进入单轴向列相;当k<0,r<1且|k|>时,系统由各向同性相经一级相变进入单轴相,再经二级相变进入双轴向列相,随着|k|的增大,一级相变消失,变为弱一级相变或连续相变.当k<0且|k|>r=1时,系统由各向同性相经一级相变进入双轴相,随着|k|的增大,一级相变消失,变为二级相变.
Abstract:
The phase transitions in V-shaped m o lecular system where the tw om o lecu lar arm s a re connected by a flex ible chain are stud ied. Based on a sim ple interaction energy be tw een mo lecu les and the approx ima tion o fm ean- fie ld theory, o rder param ete rs of equ ilibrium state as functions of reduced temperature, and phase diagram s in the p lane o fm o lecu lar structure and temperature are obta ined. The resu lts show tha t the phase transition temperatures are re lated to the elastic streng th o f flex ible cha in k and ratio of tw o arm s length r. When |k|>, or k< but |k|>, as the tem pera ture decreases, system undergoes a first orde r transition from iso trop ic phase to un iax ia l phase. W henk<, r< and |k|>, system has a first order phase trans ition from iso trop ic to uniax ia l phase, then a second o rder phase transition from un iax ial to biax ia l phase. When |k|> continues to inc rease, the first o rderw ill change into aw eak first order or a con tinuous trans ition. When |k|> and|k|> r= 1, system has a first o rder phase transition from iso trop ic to b iax ia l phase. A s | k | inc reases, the first order changes into a second orde r phase transition.

参考文献/References:

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[ 2] DeM a tte is G, V irg a E G. T ricr itical po ints in b iax ia l liquid crysta l phases[ J]. Phys Rev E, 2005, 71: 061703 1-8.
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备注/Memo

备注/Memo:
基金项目: 江苏省普通高校自然科学研究项目( 07JKD140095 ). 通讯联系人: 刘 红, 博士, 教授, 研究方向: 液晶物理理论. E-mail:liuhong@ njnu. edu. cn
更新日期/Last Update: 2013-04-08