title: Crystal-like nature of acoustic excitations in glassy ethanol.
abstract: We report on inelastic x-ray scattering experiments on crystalline and glassy phases of ethanol in order to directly compare the influence of disorder on high frequency acoustic excitations. We find that both the dispersion and the line-width of the longitudinal acoustic excitations in the glass are the same as in the polycrystal in the reciprocal space portion covering the 1st and 2nd Brillouin zones. The structural disorder is found to play little role apart from an intrinsic angular averaging, and the nature of these excitations must essentially be the same in both glass and poly crystal.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Matic
authors.forename: C
authors.initials: C
authors.lastname: Masciovecchio
authors.forename: D
authors.initials: D
authors.lastname: Engberg
authors.forename: G
authors.initials: G
authors.lastname: Monaco
authors.forename: L
authors.initials: L
authors.lastname: Börjesson
authors.forename: S C
authors.initials: SC
authors.lastname: Santucci
authors.forename: R
authors.initials: R
authors.lastname: Verbeni