Both steady-state current and dielectric-loss measurements were performed on a liquid-crystalline material, 4-(trans-4-pentylcyclohexyl)benzonitryl, in an isotropic liquid phase, which provide information on generation and behavior of ions, dominating DC and AC conductivity, respectively. The frequency dependence measurements of dielectric-loss can successfully estimate such characteristics of ions as total quantity of electricity, diffusion constant (mobility), and the size. With help of chemical analysis like ion chromatography and semi-empirical quantum chemical computation, the majority of ions, especially dominating AC conductivity, were estimated to be inorganic cations with Stokes' radius of around 2 × 10−8(cm), either naked or hydrated, and solvated ions with Stokes' radius of around 5 × 10−8(cm), most probably with the liquid-crystalline molecules at the solvation number of 1.2 in average. The present microscopic investigation of conduction mechanism is of great help for development of liquid-crystalline materials, especially for use in sophisticated displays with excellent picture quality.
