TY - JOUR
T1 - Hydrogen release from Li alanates originates in molecular lattice instability emerging at ∼ 100 K
AU - Tomiyasu, K.
AU - Sato, T.
AU - Horigane, K.
AU - Orimo, S.
AU - Yamada, K.
N1 - Funding Information:
We thank Dr. K. Ikeda, Dr. S. Iikubo, Dr. R. Kiyanagi, and Dr. Y. Ishikawa for the preliminary experiments and the helpful discussions, Dr. H. Nakamura and Dr. M. Machida for the fruitful discussion on the first-principle calculations, Dr. K. Iwasa for providing the extra beam time on TOPAN, and Mr. K. Nemoto and Mr. M. Ohkawara for supporting the experiments at JAEA. This study was financially supported by the Exploratory Research Program for Young Researchers from Tohoku University, and by Grants-in-Aid for Young Scientists (B) (22740209), Priority Areas (22014001), Scientific Researches (S) (21224008) and (A) (22244039), and NEXT Program (GR008) from the MEXT, Japan, and JSPS.
PY - 2012/5/7
Y1 - 2012/5/7
N2 - 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.
AB - 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.
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U2 - 10.1063/1.4712053
DO - 10.1063/1.4712053
M3 - Article
AN - SCOPUS:84862107032
SN - 0003-6951
VL - 100
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 19
M1 - 193901
ER -