Dynamic light-scattering studies of longitudinal and shear waves in a molecular liquid

Abstract

We have obtained new light scattering data on triphenylphosphite in both the viscoelastic and glassy regimes. We have developed a means of studying the Brillouin lineshapes and have determined that they are Lorentzian throughout. We found that in the glass the Brillouin linewidth increases with the rate of thermal quenching. And we analyzed the linewidth and shift data, both ours and that of others, in terms of the variable kη, where k is the scattering wavevector and η is the coefficient of shear viscosity; we discuss the weakness and strengths of such an analysis.