Inelastic light scattering study of hydrogen-bonded glass formers: Glycerol and ethanol

Temperature dependences of the structural relaxation time τα(T) of two hydrogen-bonded glass formers, glycerol and ethanol, were investigated by depolarized light scattering technique. τα(T) of glycerol demonstrates a transition from the Arrhenius law at high temperatures to a non-Arrhenius behavior at TA ~ 366 K. Combination of derivative analysis results for τα(T) from light scattering and dielectric spectroscopes reveals this transition near ~ 200 K in the case of ethanol. The obtained values of TA are close to the temperatures below which the excess of the Landau-Placzek ratio, associated with the appearance of locally favored structures, was observed earlier.