Electric behaviour of a Schiff's base liquid crystal compound doped with a low concentration of BaTiO3 nanoparticles

We report here a low frequency (1 Hz-10 MHz) dielectric study of a Schiff base liquid crystal compound, N-(4-n-Pentyloxybenzalidene) 4′-n-Pentylaniline (in short 5O.5) dispersed with Barium titanate (BaTiO3) nanoparticles (0.4%). The compound 5O.5 exhibit N, SmA, SmC, SmF and SmG phases. The isotropic-nematic phase transition temperature and the dielectric anisotropy (∆ ε) have been determined. The compound in pure state exhibits negative dielectric anisotropy. The effect of the ferroelectric nanoparticles (FNPs) on dielectric permittivity and dielectric anisotropy as a function of temperature as well as frequency has been discussed. It has been found that due to permanent dipole moment of FNPs, the majority of ions in isotropic and nematic phases gets trapped, consequently Maxwell-Wagner-Sillars (MWS) effect has diminished. The conductivity of the dispersed samples was found to decrease. Comparative dielectric relaxation behavior of the liquid crystal molecules of pure and BaTiO3 dispersed samples are discussed in nematic, SmA and SmC phases of the compound.