On the absence of a positive sound dispersion in the THz dynamics of glycerol: an inelastic x-ray scattering study
- BNL
The high frequency transport properties of glycerol are derived from inelastic x-ray scattering spectra measured at different pressures and compared with ultrasound absorption data. As a result, the presence of two distinct relaxation processes is inferred: a slow one, occurring in the GHz window and having an essentially structural character, and a fast one, related instead to microscopic degrees of freedom. While the former originates a neat increase of the apparent, i.e. frequency-dependent, sound velocity, the latter induces no visible dispersive effects on the acoustic propagation. The observed behavior is likely paradigmatic of all glass formers near or below the melting and it is here discussed and explained in some detail.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- DOE - BASIC ENERGY SCIENCES
- OSTI ID:
- 1049539
- Journal Information:
- J. Phys. Condens. Matter, Vol. 24, Issue (37) ; 2012; ISSN 0953-8984
- Country of Publication:
- United States
- Language:
- ENGLISH
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