The vibrational properties of xenon hydrate: an inelastic incoherent neutron scattering study

Download
  1. Get@NRC: The vibrational properties of xenon hydrate: an inelastic incoherent neutron scattering study (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1063/1.1446426
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleThe Journal Of Chemical Physics
Volume116
Issue9
Pages37953799; # of pages: 5
Subjectneutron diffraction; phonons; thermal conductivity; vibrational modes; water; xenon
AbstractWe report results from a high-resolution, incoherent inelastic neutron scattering (IINS) study of xenon hydrate. This study extends previous work in which the existence of a strong coupling between localized guest vibrations and the lattice modes was shown1 for the first time [Tse et al., Europhys. Lett., 54, 354 (2001)]. This guest�host coupling might be responsible for the glass-like temperature dependence of the thermal conductivity of the crystalline gas hydrates. Our experiment focused on the low-frequency phonon density of states of the ice-like water lattice of xenon hydrate. We found two broad maxima in the density of states (DOS) at energy transfers of 7.3 and 10.3 meV. The first peak is assigned to the transverse acoustic (TA) phonons near the zone boundary and the second to the fold-back of the TA modes towards the zone center. The guest�host coupling could be confirmed by finding three distinct low energy peaks in the DOS at energy transfers of 2.05, 2.87, and 3.94 meV. In addition, another broad inelastic scattering component extending from 0 to 1.5 meV has been found, which may also be important for the low-temperature behavior of the thermal conductivity. The line positions of the coupled modes shift to higher frequencies with increasing temperature, pointing towards the importance of the repulsive part of the host�guest interaction which is responsible for the stability of gas hydrate structures.
Publication date
AffiliationNational Research Council Canada; NRC Steacie Institute for Molecular Sciences
Peer reviewedNo
NPARC number12327567
Export citationExport as RIS
Report a correctionReport a correction
Record identifier990bbafa-f02c-4dde-86a8-f54be01f435e
Record created2009-09-10
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)