Applied Physics Letters
We investigate the influence of the electric field on the conductivity of an antiferroelectric liquid crystal formed by bananalike molecules. Our experimental analysis shows that large deviations of the current from a pure Ohmic behavior are observed for applied voltage of the order of the ones used for the determination of the spontaneous polarization in these types of materials. The measurements are performed in the isotropic and B-2 phases. In the isotropic phase these deviations are interpreted in terms of the model proposed by Onsager, according to which, for weak electrolyte, the conductivity depends on the actual electric field present in the liquid. In the ordered phase we show that they are partially due to the external field induced reorientation of the director structure. A good agreement between the model and the experimental data is obtained, and an estimate of the coefficients taking into account the effect of the electric field on the conductivity is deduced. The relevance of this effect on the experimental determination of the spontaneous polarization is found to be of the order of 10%.
Martins, O. G.; Barbero, G.; Pedreira, A. M.; Jakli, Antal; Sawade, H.; and Neto, A. M. F. (2006). Electric Field Dependence of the Electric Conductivity in Liquid Crystals Made of Bent-Core Molecules. Applied Physics Letters 88(21). doi: 10.1063/1.2206684 Retrieved from http://digitalcommons.kent.edu/cpippubs/155