Magnetic-field-induced changes of the isotropic-nematic phase transition in side-chain polymer liquid crystals

被引:9
作者
Boamfa, MI
Viertler, K
Wewerka, A
Stelzer, F
Christianen, PCM
Maan, JC
机构
[1] Univ Nijmegen, Inst Mat Res, High Field Magnet Lab, NL-6525 ED Nijmegen, Netherlands
[2] Graz Univ Technol, Inst Chem & Technol Organ Mat, A-8010 Graz, Austria
来源
PHYSICAL REVIEW E | 2003年 / 67卷 / 05期
关键词
D O I
10.1103/PhysRevE.67.050701
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
The isotropic-nematic (I-N) phase transition of side-chain polymer liquid crystals is intrinsically a weak first-order transition with a biphasic region spread over a wide temperature interval. In the presence of high magnetic fields we find the I-N transition to become a strong first order. The I-N biphasic region shrinks its temperature window as larger magnetic fields are applied, until it completely disappears and the transition completes at a fixed temperature. We interpret this behavior as a consequence of the nonlinear coupling of the magnetic field to the system free energy, via the suppression of the order fluctuations in the nematic mesophase at the I-N transition crossing.
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页数:4
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