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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:30 |
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Conference: Bucharest University Faculty of Physics 2001 Meeting
Section: Atomic and Molecular Physics; Astrophysics
Title:
Liquid crystal flexoelectric role in meniscus conduction
Authors:
Anca Alexe/Ionescu**, Emil Barna*, Andrei Ionescu*, and Nicola Scaramuzza***
Affiliation:
*) Physics Faculty, University of Bucharest, **) University "Politehnica", Bucharest,
***)Dept. of Physics, University of Calabria
E-mail
Keywords:
Abstract:
Experimental evidence has been obtained for the important role of the transversal surface conduction in LC cells. Liquid crystal 6CB (sextyl-cyanobiphenyl K18 by Merck) is introduced between the ITO deposited plates of a rectangular capillary, 23 micrometers thick. Current/voltage measurements done in the liquid crystal mesophase reveal two dependencies: one of higher conductivity at low voltages and another of lower conductivity at higher voltages, whereas in the isotropic phase only the conductivity is seen at all voltages. Experiments have shown that the high conductivity regime depends on the length of the bordering meniscus formed by the liquid crystal layer. For specially prepared cells in which the meniscus is out of the electrode region only the low conductivity regime is seen. We have explained these facts in terms of a flexo-electric effect which lowers the curvature of the meniscus, decreasing thus the contact area between it and the electrodes where presumably the charge injection of the electrons is higher due to tunnelling.
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