Dielectric relaxation studies in N-(4-octyloxy-2-hydroxybenzylidene)-4-carbethoxyaniline

被引:14
作者
Dhar, R [1 ]
Gupta, M
Agrawal, VK
Singh, MK
Singh, B
机构
[1] Ewing Christian Coll, Dept Phys, Allahabad 211003, Uttar Pradesh, India
[2] Univ Allahabad, Dept Phys, Allahabad 211002, Uttar Pradesh, India
[3] Banaras Hindu Univ, Dept Chem, Varanasi 210005, Uttar Pradesh, India
关键词
permittivity and loss; dielectric relaxation; arrhenius plot; smectic A phase;
D O I
10.1080/01411590410001667617
中图分类号
O7 [晶体学];
学科分类号
0702 ; 070205 ; 0703 ; 080501 ;
摘要
Temperature dependent dielectric spectroscopy of a newly synthesized compound N-(4-octyloxy-2-hydroxy-benzylidene)-4-carbethoxyaniline, having a wide temperature range (similar to70degreesC) Smectic A (SmA) phase has been carried out in the frequency range 100 Hz-10 MHz. Dielectric permittivity and loss in the homeotropic (epsilon'(parallel to) and epsilon"(parallel to)) and planar (epsilon'(perpendicular to) and epsilon"(perpendicular to)) alignments of the molecules have been determined. Relaxation frequencies corresponding to the rotation of the molecules about their short axes have been found to lie below 1 MHz and exhibit Arrhenius behaviour. Relaxation frequencies corresponding to the rotation of the molecules about their long axes are expected to lie above 10 MHz. Dielectric anisotropy (Deltaepsilon' = epsilon'(parallel to) - epsilon'(perpendicular to)) has been found to be negative throughout the range of the SmA phase.
引用
收藏
页码:375 / 384
页数:10
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