Relaxation dynamics in glycerol studied by impulsive stimulated thermal scattering

Abstract Time resolved spectroscopy called impulsive stimulated thermal scattering (ISTS) has been carried out to investigate the dynamics of the liquid–glass transition in a supercooled polyalcohol, glycerol. The wave vector dependence of the time dependent density fluctuation has been detected by ISTS. It is found that the thermal relaxation time τ H related to thermal diffusion shows the remarkable anomaly at a temperature T hmax far above the glass transition temperature T g . Moreover, T hmax is found to depend on the wave vector. These findings are discussed in terms of phonon velocity and phonon mean free path.