Quasielastic light scattering from nematicp-methoxybenzylidene-p′−n-butylaniline (MBBA)

Abstract

The quasielastic scattering of laser light from nematic MBBA is studied utilizing homodyne procedures. The results stem from a comprehensive study of the half widths and areas of the slow mode peaks together with their temperature and angle dependence. The data taken at small angles yield the temperature-dependent ratios of the viscosity coefficients to curvature elastic constants for twist, bend, and splay. From these ratios, utilizing data of others, the temperature dependence of the twist elastic constant ${K}_{22}$, and twist, splay, and bend viscosity coefficients ${\ensuremath{\gamma}}_{1}$, ${\ensuremath{\eta}}_{s}$, and ${\ensuremath{\eta}}_{b}$, respectively, are determined. From the data taken at large angles the values of ${\ensuremath{\alpha}}_{4}^{\ensuremath{'}}$ and ${\ensuremath{\alpha}}_{v}^{\ensuremath{'}}$ (which is found to be negative) are determined at a reduced temperature, ${T}_{R}=0.96$.