Dynamics of the nonlinear dielectric properties of a nematogenic compound dissolved in a nonpolar medium

The nonlinear dielectric spectra of 4-(trans-4(')-n-hexylcyclohexyl)isothiocyanatobenzene (C(6)H(13)CyHx Ph NCS, 6CHBT) in benzene solutions were recorded in the whole concentration range up to an appearance of the two-phase isotropic and nematic region (0.82 mole fraction of 6CHBT, at 25 degreesC). Two electric fields: (i) the field of high strength (110 kV/m) and low frequency (85 Hz) causing the dielectric nonlinearity, and (ii) the probing field of low strength and high frequency (100 kHz-3 GHz), were used. At about of 0.2 mole fraction of 6CHBT the nonlinear dielectric increment becomes positive. With increasing of 6CHBT concentration the dynamics of the increment shows a critical-like behavior, which can be interpreted in terms of the reorientation of the growing pseudonematic domains in the solutions studied.