Abstract
We have used deuterium NMR spectroscopy to investigate the director dynamics in a nematic liquid crystal 4-pentyl-4'-cyanobiphenyl(5CB), confined between two glass plates. We have measured the NMR spectrum as a function of time during the rotation of the director from being initially parallel to the magnetic field to an orthogonal orientation after the application of the electric field. After the pulsed electric field is removed, the director is allowed to relax back from an initial distribution to an equilibrium alignment parallel to the magnetic field. The results are for turn-on transient the director rotates to the electric field uniformly over the slab, for turn-off transient the director relaxes ununiformly. We also calculate the director dynamics using the torque balance equations in order to make the results clear.
