Swadesh Kumar Gupta; Dharmendra Pratap Singh; Rajiv Manohar*
Abstract
The present study focuses on the effect of anatase TiO2 (titania) nanoparticles (NPs) on conductivity and polarization in a ferroelectric liquid crystal (FLC). Different dielectric and electro-optical measurements have been conducted to explore the charge transportation and polarization mechanism in ...
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The present study focuses on the effect of anatase TiO2 (titania) nanoparticles (NPs) on conductivity and polarization in a ferroelectric liquid crystal (FLC). Different dielectric and electro-optical measurements have been conducted to explore the charge transportation and polarization mechanism in titania NPs doped FLC system. Doping of titania NPs show reduced dc conductivity of doped LC system attributed to the trapping of free charges by titania NPs at its surface. Polarization has been found to increase at low fields indicating reduction of field screening effect in doped FLC system. Optical response of the doped FLC system has been improved due to decreased intervention of ionic charges particularly at small electric fields. The present study will be helpful in minimizing the slow response problems and the grey level shift in liquid crystal devices which arise due to ionic effects.
Dharmendra Pratap Singh; A. C. Pandey;Rajiv Manohar; Swadesh Kumar Gupta
Abstract
The ZnO1-xSx, metal oxide nanoparticles (MNPs) have been dispersed in the ferroelectric mesophase (FLC). The electrical properties and dielectric relaxation processes have been studied for the MNPs dispersed FLC system with the variation of frequency and temperature. The dielectric measurements have ...
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The ZnO1-xSx, metal oxide nanoparticles (MNPs) have been dispersed in the ferroelectric mesophase (FLC). The electrical properties and dielectric relaxation processes have been studied for the MNPs dispersed FLC system with the variation of frequency and temperature. The dielectric measurements have been carried out in the frequency interval of 1Hz-10MHz to investigate different relaxation processes. Three different relaxation modes have been observed in the case of the pure FLC at frequency 2.5Hz, 20Hz and Goldstone relaxation mode at 200Hz. The addition of MNPs, suppressed the relaxation mode observed at 2.5 Hz for the pure FLC whereas the relaxation mode observed at 20 Hz is shifted to the higher frequency side. The conductivity and the relative permittivity of the pure FLC have also been enhanced by the dispersion of the MNPs. The present investigation establishes the MNPs as an intelligent material to tune the relaxation process and to enhance the conductivity of the materials.
