Hydrides have been expected to be high gravimetric and volumetric density hydrogen storage materials . Recently the hydrides also showed some interesting materials properties which were lithium-ion conductor (ex. LiBH_4 ) , semi-conductor (ex. SrAlSiH) , and so on. In order to understand the interesting properties, the structural investigations are one important research.
On the other hand, it is very difficult to detect hydrogen by x-ray because x-ray scattering occurs by interaction with the electrons.
However neutrons were scattered by atomic nuclei and it is possible to identify hydrogen (deuterium) atomic positions. In addition, dynamics of hydrides studied by inelastic neutron scattering is also one interesting study because inelastic scattering cross section of hydrogen (82.02
barns) is approximately ten times as large as those of the most other elements (less than 12 barns). Therefore, neutron scattering experiments of hydrides are essential for research and developments of the hydrides.
For the reason, a lot of structures and dynamics of hydrides have been elucidated by neutron scattering studies [4, 5].
In this seminar, I will show the elastic (structure) and inelastic
(dynamics) neutron scattering studies on Ca-Al-H system that are an interesting hydrogen storage material .
 S. Orimo, Y. Nakamori, J.R. Eliseo, A. Züttel, C.M. Jensen, Chem.
Rev. *107*, 4111, (2007).
 M. Matsuo, Y. Nakamori, S. Orimo, H. Maekawa, H. Takamura, Appl.
Phys. Lett. *91*, 224103, (2007).
 T. Bjorling, D. Noréus, K. Jansson, M. Andersson, E. Leonova, M.
Edén, U. Hålenius, U. Häussermann, Angew. Chem. Int Ed *44*, 7269 *(2005)*
 B.C. Hauback, Z. Kristallogr. *223*, 636 (2008).
 S.F. Parker, Coord. Chem. Rev. *254*, 215 (2010).
 T. Sato, M.H. Sørby, K. Ikeda, S. Sato, B.C. Hauback, S. Orimo, J.
Alloys Compd. *487*, 472 (2009).