Hydrogen release from Li alanates originates in molecular lattice instability emerging at ∼ 100 K

K. Tomiyasu, T. Sato, Kazumasa Horigane, S. Orimo, K. Yamada

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Lattice vibrations from 20 K to room temperature in lithium alanates LiAlH 4 and Li 3AlH 6, which decompose to release hydrogen over 423 K, were investigated by neutron spectroscopy. For both alanates, the overall spectra already start to broaden at 100-150 K with increasing temperature. The spectral lines assigned to the librational (rotational) modes of the polyhedral Al hydrido complexes, [AlH 4] - and [AlH 6] 3-, exhibit not only broadening but also softening at around 250-300 K. These results suggest that the decomposition stems from low-temperature bulk lattice instability/ anharmonicity, in particular, due to the weakening of binding between the complexes and their surroundings.

Original languageEnglish
Article number193901
JournalApplied Physics Letters
Volume100
Issue number19
DOIs
Publication statusPublished - May 7 2012
Externally publishedYes

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lattice vibrations
stems
softening
line spectra
emerging
lithium
decomposition
neutrons
room temperature
hydrogen
spectroscopy
temperature

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Hydrogen release from Li alanates originates in molecular lattice instability emerging at ∼ 100 K. / Tomiyasu, K.; Sato, T.; Horigane, Kazumasa; Orimo, S.; Yamada, K.

In: Applied Physics Letters, Vol. 100, No. 19, 193901, 07.05.2012.

Research output: Contribution to journalArticle

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AU - Yamada, K.

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