Heat Convection in a Nematic Liquid Crystal

Abstract

We present a theoretical and experimental study of the thermal properties of a well aligned nematic Liquid Crystal in a vertical temperature gradient. Due to the long time constant of the relaxation of the director and to the anisotropy of the heat conductivity, the value of the temperature gradient threshold for convective instabilities is strongly modified as compared to the isotropic case. Experiments on planar MBBA films show a drastic reduction of the threshold. A detailed description of the shape and temperature distribution of the convective rolls is given.