Dynamical Behavior of a Nematic Liquid Crystal just above the Nematic-Isotropic Transition from Spin-Lattice Relaxation

We report here the proton spin-lattice relaxation time ${\left(T_1\right)}_{\mathrm{CF}}$ measured in $p$-methoxybenzylidene $p-n$ butylaniline at two frequencies in a temperature range of about 25°C just above the nematic-isotropic transition. We have determined the correlation time for critical fluctuations, ${\tau }_{\mathrm{CF}}$, using a simple extension of the Bloembergen-Purcell-Pound theory which relates ${\tau }_{\mathrm{CF}}$ and ${\left(T_1\right)}_{\mathrm{CF}}$. The temperature dependence ${\tau }_{\mathrm{CF}}$ is in good agreement with the de Gennes theory and with experimental results of Stinson and Litster.