Investigation of dielectric, optical and zeta potential properties of pure and zinc ferrite nanoparticles dispersed nematic liquid crystal PCH5

Abstract

The present work reports the results on dielectric and optical properties, and zeta potential of pure and zinc ferrite magnetic nanoparticles (ZnFe2O4 NPs) dispersed nematic liquid crystals (NLC) 4-(trans-4'-n-pentylcyclohexyl) benzonitrile (PCH5). The ZnFe2O4 NPs of three different concentration 0.25, 0.5 and 1.0 wt% have been dispersed in host nematic. The effect of ZnFe2O4 NP dispersion in NLC PCH5 on dielectric permittivity, dielectric anisotropy, ac conductivity, photoluminescence, Raman spectra and zeta potential has been studied. It has been observed that these properties are influenced by the concentrations of NPs in host nematic and applied electric field. Significant decrease in dielectric permittivity and dielectric anisotropy due to the presence of NPs in host nematic matrix has been observed. For the NP concentrations of 0.25 and 0.5 wt% in PCH5, photoluminescence intensity is increased, but it is decreased for the 1.0 wt% concentration of NPs in host nematic matrix. The numerical values of zeta potential are decreased with the concentrations of NPs. This result provides useful information on the stability and aggregation dynamics of the dispersed systems. In the profile of Raman spectra, variation in intensities is found for different orientations. An effort has been made to explain the observed results on the basis of interaction between NPs and nematic molecules. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.