Low frequency dielectric spectroscopy of two room temperature chiral liquid crystal mixtures

被引：44
作者：
Pandey, MB
Dhar, R [1 ]
Agrawal, VK
Khare, RP
Dabrowski, R
机构：
[1] Ewing Christian Coll, Dept Phys, Allahabad 211003, Uttar Pradesh, India
[2] Univ Allahabad, Dept Phys, Allahabad 211002, Uttar Pradesh, India
[3] Mil Univ Technol, PL-01489 Warsaw, Poland
来源：
PHASE TRANSITIONS | 2003年 / 76卷 / 11期
关键词：
chiral liquid crystal mixtures; dielectric spectroscopy; ionic conduction; SmC* phase;
D O I：
10.1080/01411590310001596400
中图分类号：
O7 [晶体学];
学科分类号：
0702 ; 070205 ; 0703 ; 080501 ;
摘要：
Dielectric spectroscopy of two room temperature chiral liquid crystal mixtures (W-96 and W-97) have been carried out in the frequency range of 100mHz-10MHz. Low frequency dielectric relaxation modes corresponding to collective behavior of molecules (Goldstone- and soft-modes) in the SmC* phase have been found to be masked by the ionic conductance. Two slow modes of dielectric relaxation due to the ionic conductance have been detected (below 15Hz) in planar-aligned samples. It has been observed that the effect of ionic conductance decreases with the number of thermal annealing cycles on the materials. With large number of thermal annealing cycles it has been possible to wipe out the effects of ionic conductance and then to detect other weak modes of dielectric relaxation which are otherwise masked.
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页码：945 / 958
页数：14
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