Measurements are reported of the frequency dependence of the conductivities sgr;perp;and sgr;par;in some nematic liquid crystals with strong positive dielectric anisotropy which are nematic at room temperature. The conductivity relaxation which causes sgr;par;to increase already at frequencies 100 Hz in highly deionized liquid crystals are shown to be quantitatively in agreement with the dispersion of the orientation polarization of the molecules. The magnitude and sign of the conduction anisotropy sgr;par;minus;sgr;perp;is shown to be strongly frequency dependent. The relaxation times tgr;perp;and tgr;par;due to the respective rotation of the molecules in a plane perpendicular and parallel to their long axes were determined.
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