Dielectric constant and conductivity anisotropy measurements of Schiff base liquid crystal

The liquid crystal (LC) compound with the central linkage group Schiff-base was studied. The molecular structure was characterized with FTIR. Mesomorphic properties were characterized using differential scanning calamity (DSC) and polarizing optical microscopy (POM). The dielectric constant (ε) with conductivity (σ) and dielectric anisotropy (Δε) have been measured in the frequency range of 100 Hz to 100 MHz from room temperature to l00 °C. Dielectric constants parallel and perpendicular to helical axes (εII and ε ⊥ ), the dielectric anisotropy (Δε = εII –ε ⊥) and conductivity (Δσ) have been determined in different mesophases. Activation energy ( Eac ) of the a.c. conduction process and threshold voltage (V th ) of the sample sandwiched in the liquid crystal cell have been determined in different mesophases. The electro-optic effect was also studied at liquid crystal phase temperatures. The Schiff-base liquid crystal sample exhibiting a nematic phase.