Observation of Linear and Nonlinear Relaxations of Fluid Dynamical Motion in Liquid Crystal

Abstract
The fluid motion induced by the external electric field in nematic ( p -ethoxy-benzylidene)- p -butylaniline was observed by detecting the electrical conductivity. The relaxation time of this motion was determined in the cases of the linear and nonlinear responses. The results are analysed on the basis of the idea that the convection instability can be described as a second order phase transition, and are consistent with the time dependent Ginzburg-Landau theory within the molecular field approximation. It gives an example of the linear-nonlinear crossover behavior of the critical exponent of the relaxation time.