The Structure and Properties of LaNi5H3

The structure of an intermediate phase(LaNi5H(D)3) in the LaNi5-H2 system has been refined using high resolution time-of-flight neutron powder diffraction data. The structure is described in the space group P6/mmm and the unit cell dimensions are a =5.302 (5) Å and c =4.066(3)Å. The interstitial deuterium sites were discussed and the content of deuterium was confirmed by both neutron diffraction and a volumetric measurement. The behaviors of LaNi5H3 at room temperature were investigated using a in-situ X-ray diffraction method. It was found that the LaNi5H3 phase was not stable at room temperature.