FAST DYNAMICS OF GLASS-FORMING GLYCEROL

The vibrational and relaxational dynamics of glycerol has been measure d by incoherent neutron scattering for energy transfers from some 10 m u eV to several 10 meV, and for temperatures from 4 to 413 K. On heati ng towards and above the glass transition, scattering from low-frequen cy vibrations shows an unspectacular increase that is consistent with ultrasonic data. We propose using the vibrational density of states fo r calculating the Fourier transformed time correlation function S(q,t) without the cutoff usually imposed by the kinematics of neutron scatt ering. For high temperatures and low frequencies, structural relaxatio n is well described by the empirical Kohlrausch law. There is no exten ded crossover region between vibrations and structural relaxation.