Published online by Cambridge University Press: 26 February 2011
An overview of the pressure-induced transformations and order-disorder phenomena in LiAlH4 (up to 7 GPa) and LiNH2 (up to 25 GPa) are presented. The analysis of pressure-induced changes in Raman spectra suggest a phase transition at ∼3 GPa for LiAlH4 and ∼14 GPa for LiNH2. New results on the metastable recovery of the high pressure β-LiAlH4 phase are also presented. An examination of the lattice translational and librational modes reveals that the high pressure β-LiAlH4 phase is disordered while there is evidence of orientational ordering in the high pressure beta-LiNH2 phase.