CAPACITIVE TRANSIENTS DURING FREEDERICKSZ TRANSITION IN 7CB AND 8CB

The dynamic behaviour around the electrically driven Freedericksz transition in the nematic liquid crystals 7CB and 8CB has been studied experimentally by measuring the time dependence of capacitance of a thin layer of planarly oriented sample. The initial parts of both growth and decay of capacitance in both samples are found to be exponential in nature. Beyond the initial exponential part, we find that in 7CB, close to the N-I transition, the decay of capacitance is oscillatory. The rotational viscosity coefficient gamma1 has been determined from the decay rates of capacitance.