Transient photoconductivity, dielectric anisotropy and elastic constants properties of 4-n-hexyl-4’-cyanobiphenyl (6CB) nematic liquid crystal

Abstract

The elastic constants, dielectric anisotropy and transient photoconductivity properties of 4-n-hexyl-4’-cyanobiphenyl (6CB) nematic liquid crystal have been investigated. The structure of the LC changes from positive to negative dielectric anisotropy at a critical frequency value, f_c. The f_c values at dark and laser illumination were found to be 630.50 kHz and 653.94 kHz, respectively. The laser illumination increases critical frequency value of the LC. The splay K₁₁ and bend K₃₃ values at dark and laser illumination were determined and these values decrease with frequency and laser illumination. The dielectrical relaxation of the LC indicates a non-Debye type relaxation behavior. The application of the laser significantly alters the shape of the transient photoconductivity. The mobility values at dark and laser illumination were found to be 0.196x10^-6 cm²/V.s and 0.134x10^-6 cm²/V.s, respectively. The mobility of the charge carriers decreases with laser illumination. The transient photoconductivity of the LC increases with laser illumination.