Reversible phase transition in LiAlH4 under high-pressure conditions -: art. no. 180101

The structural stability of the hydrogen storage compound LiAlH4 was studied by Raman spectroscopy in the pressure interval 0-6 GPa. A slow phase transition from alpha-LiAlH4 to a beta phase was observed to occur between 2.2 and 3.5 GPa. The phase transition is reversible and a reverse transformation to alpha-LiAlH4 was observed below 1.4 GPa. Analysis of Raman spectra from beta-LiAlH4 shows that they cannot be explained by the theoretically predicted alpha-NaAlH4-type structure with I4(1)/a symmetry.