Dielectric Relaxation of Long Molecules in Nematic Host Matrices

Abstract

Abstract The relaxation times τ of the slowest processes in the parallel dielectric permittivity of various nematic guest-host systems have been measured as a function of temperature. A correlation between τ and its temperature dependence is found, indicating increasing temperature dependence for increasing τ, independent of structural details of the guest molecules or properties of the host matrices which, however, had similar clearing temperatures. Alternations in τ for a homologous series of guest molecules are observed. Increasing host permittivity leads to increased values of τ while the viscous properties of the host show little influence on τ.