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

Abstract

We report here the proton spin-lattice relaxation time ${({T}_{1})}_{\mathrm{CF}}$ measured in $p$-methoxybenzylidene $p\ensuremath{-}n$ butylaniline at two frequencies in a temperature range of about 25\ifmmode^\circ\else\textdegree\fi{}C just above the nematic-isotropic transition. We have determined the correlation time for critical fluctuations, ${\ensuremath{\tau}}_{\mathrm{CF}}$, using a simple extension of the Bloembergen-Purcell-Pound theory which relates ${\ensuremath{\tau}}_{\mathrm{CF}}$ and ${({T}_{1})}_{\mathrm{CF}}$. The temperature dependence ${\ensuremath{\tau}}_{\mathrm{CF}}$ is in good agreement with the de Gennes theory and with experimental results of Stinson and Litster.