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Low-frequency relaxation modes in ferroelectric liquid crystal/gold nanoparticle dispersion: impact of nanoparticle shape

Podgornov, F. V. and Wipf, R. and Stühn, B. and Ryzhkova, A. V. and Haase, W. (2016):
Low-frequency relaxation modes in ferroelectric liquid crystal/gold nanoparticle dispersion: impact of nanoparticle shape.
In: LIQUID CRYSTALS, TAYLOR & FRANCIS LTD, pp. 1536-1547, 43, (11), ISSN 0267-8292, [Article]

Abstract

Low-frequency (1 mHz-100 Hz) dielectric relaxation modes were experimentally studied in ferroelectric liquid crystal (FLC)/gold nanoparticles (nanospheres and nanorods) dispersion. It was demonstrated that the dielectric spectra of nanodispersion are strongly influenced by the shape of nanoparticles. Using different formalisms of the impedance spectroscopy, three possible low-frequency relaxation processes were found in the dispersions and the pure FLC. Due to the electrical double layers (EDLs) near nanoparticles and the alignment layers, one can observe the relaxation of the EDL polarisation around the nanoparticles (Schwarz's relaxation) and near the driving indium tin oxide (ITO) electrodes (electrode polarisation). The other possible relaxation process is interfacial polarisation (Maxwell-Wagner mode) in which the frequency is unaffected by the nanoparticles. It was shown that Schwarz's relaxation frequency strongly depended on the shape and size of the nanoparticles. Moreover, dispersion of nanoparticles significantly reduced direct current conductivity of the FLC mixture. GRAPHICS] .

Item Type: Article
Erschienen: 2016
Creators: Podgornov, F. V. and Wipf, R. and Stühn, B. and Ryzhkova, A. V. and Haase, W.
Title: Low-frequency relaxation modes in ferroelectric liquid crystal/gold nanoparticle dispersion: impact of nanoparticle shape
Language: Afar
Abstract:

Low-frequency (1 mHz-100 Hz) dielectric relaxation modes were experimentally studied in ferroelectric liquid crystal (FLC)/gold nanoparticles (nanospheres and nanorods) dispersion. It was demonstrated that the dielectric spectra of nanodispersion are strongly influenced by the shape of nanoparticles. Using different formalisms of the impedance spectroscopy, three possible low-frequency relaxation processes were found in the dispersions and the pure FLC. Due to the electrical double layers (EDLs) near nanoparticles and the alignment layers, one can observe the relaxation of the EDL polarisation around the nanoparticles (Schwarz's relaxation) and near the driving indium tin oxide (ITO) electrodes (electrode polarisation). The other possible relaxation process is interfacial polarisation (Maxwell-Wagner mode) in which the frequency is unaffected by the nanoparticles. It was shown that Schwarz's relaxation frequency strongly depended on the shape and size of the nanoparticles. Moreover, dispersion of nanoparticles significantly reduced direct current conductivity of the FLC mixture. GRAPHICS] .

Journal or Publication Title: LIQUID CRYSTALS
Volume: 43
Number: 11
Place of Publication: 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND
Publisher: TAYLOR & FRANCIS LTD
Uncontrolled Keywords: Ferroelectric liquid crystals; gold nanoparticles; relaxation modes; dielectric spectroscopy; electric double layers
Divisions: 05 Department of Physics > Institute for condensed matter physics > Experimental Condensed Matter Physics
05 Department of Physics > Institute for condensed matter physics
05 Department of Physics
Event Location: 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND
Date Deposited: 30 Jan 2017 12:10
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