کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5413089 1393466 2009 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enhancement of Freedericksz's threshold voltage of nematic liquid crystals in thin cells
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Enhancement of Freedericksz's threshold voltage of nematic liquid crystals in thin cells
چکیده انگلیسی
We report the measurement of Freedericksz's threshold voltage (Vth) in two pure calamatic nematic as well as a mixture of a calamatic nematic and a bent core (banana) liquid crystal at different thicknesses, in the ranges 1-3 μm and 7 to 15 μm cells. Rubbed polyimide-coated glass plates are used to get planar alignment of the nematic director. We show that the transmitted intensity varies gradually across the transition region with the applied voltage in the thin cells compared to the thick cells. We find a significant enhancement of Vth in thin cells in both the compounds and in the mixture and the enhancement is larger at as the temperature is lowered in the nematic phase. Part of it is contributed by the enhancement of the orientational order parameter (Vth2 ~ S) in thin cells. Finally we discuss the role of ionic contribution to increase the space charge polarization in thin cells in further enhancing the threshold voltage.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Liquids - Volume 147, Issue 3, 15 August 2009, Pages 145-148
نویسندگان
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