Debye type dielectric relaxation in carbon nano-balls' and 4-DMAABCA acid doped E7 coded nematic liquid crystal

Senturk E., Okutan M., San S. E., Koysal O.

Journal of Non-Crystalline Solids, vol.354, no.30, pp.3525-3528, 2008 (SCI-Expanded) identifier identifier


The electrical properties of carbon nano-balls' and 4-dimethylaminoazobenzene-2′-carboxylic acid doped dispersed nematic liquid crystal composite were investigated by impedance spectroscopy technique. The conductivity and capacitance were measured in the frequency range 100 kHz-1 MHz and temperature range 300-380 K. The loss peak was observed in the dielectric loss spectra and was identified as nearly-Debye type relaxation. Cole-Cole plots have been used to describe the characteristic changes of electrical properties in mentioned temperature interval. The sample presents monodispersive relaxation behavior with a relaxation time of ∼10-7 s. The relaxation process is attributed to the dipolar rotation of the long molecular axis and the activation energy is found to be 0.097 eV. © 2008 Elsevier B.V. All rights reserved.