Inelastic neutron scattering studies of TbNiAlH1.4and UNiAlH2.0hydrides
The optical vibrations of hydrogen in TbNiAlH{sub 1.4} and UNiAlH{sub 2.0} were investigated by means of inelastic neutron scattering. The experimental data were analysed, including multiphonon neutron scattering contributions, calculated in an isotropic harmonic approximation. At least two fundamental H optical peaks were observed in TbNiAlH{sub 1.4}, and were assigned to the vibrational modes of hydrogen atoms occupying different interstitial sites in the metal sublattice. The high-energy part of the UNiAlH{sub 2.0} spectra is characterized by strong anharmonicity, and a broad fundamental band. The latter can be accounted for by a large dispersion of phonon modes due to the strong H-H interactions, and/or different metal-hydrogen force constants, which may originate from different metal atoms surrounding the H atoms in the unit cell.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 15004071
- Journal Information:
- Journal of Physics. Condensed Matter, Vol. 15, Issue 17; ISSN 0953-8984
- Publisher:
- IOP Publishing
- Country of Publication:
- United States
- Language:
- English
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