Pressure induced phase transitions in the promising hydrogen store NaMgH3

Hydride perovskites (ABH3) are promising candidates for reversible hydrogen storage because of their high hydrogen capacity. Pressure induced structural transformations in (oxide and fluoride) perovskites have shown to lead to original atomic arrangements with remarkable functional properties. We are studying how hydrogen storage performance in perovskite can be tailored using high pressure, in particular how the lattice changes affect the thermodynamics of the hydride. By use of DFT calculations, our colleagues have predicted that NaMgH3 undergoes a phase transformation at about 10 GPa. Our goal is to investigate the structural changes of the NaMgH3 perovskite by use of in situ X ray diffraction in the pressure range 0- 40 GPa and temperature range 300 – 600K. So far, no experimental data have been published about pressure induced structural changes in hydride perovskite, we believe that new insights about hydride stability and metal-hydrogen bonding could arise from this study.