| Autor: |
Vovk, V. E., Koval'chuk, A.V., Lebovka, N. |
| Předmět: |
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| Zdroj: |
Liquid Crystals; Jan2012, Vol. 39 Issue 1, p77-86, 10p |
| Abstrakt: |
The microstructure and dielectric properties of nematic liquid crystals (LCs) E25M (cyanobiphenyls/terphenyl mixture) doped by modified fullerene mC60 (with weight concentration C within 0–3 wt%) were investigated at different temperatures (298–343 K). The fullerene C60 was modified by 1,8-octanediamine in order to improve its affinity to LC media. Sandwich-type 25 μm thick glass cells with planar (┴) and homeotropic (||) alignments of LC media inside them were used. The optical microscopic data evidenced the presence of more homogeneous spatial distribution of aggregates for || alignment in comparison to that observed for || alignment. The dielectric studies revealed different dielectric properties (activation energies W, relaxation times τ and bulk electrical conductivities σ B ) of pure E25M and mC60+E25M mixtures in dependence of medium alignment. Different inequalities W || < W ┴ in pure Е25М and W ┴ < W || in mC60+Е25М mixtures were observed for the near-electrode layers and the bulk electrical conductivity components. This evidenced the presence of different charge transfer mechanisms, depending on alignment of the LC medium. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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