Structural changes of Mg2NiH4 under high hydrogen pressures

Phase transformations of Mg2NiH4 at high-pressure thermal treatment

“…The cell parameter for the cubic phase that was refined with PIRUM is summarized in Table 1 for different experimental conditions. In fact, as was illustrated in our previous paper [11], even at room temperature the compression in the interval of 1.3-2.0 GPa induces the transformation of the LT-form into the cubic form (#2), in the same way as observed in ball-milled Mg 2 NiH 4 [9]. The cell dimension became smaller and the symmetry increased.…”

“…1 are shown the spectra from the experiment with LiAlH 4 as hydrogen source. The spectra from the experiments with NaBH 4 + Ca(OH) 2 as hydrogen source and without hydrogen source can be found in our previous paper [11]. Results obtained with the two hydrogen sources were the same.…”

“…As an internal hydrogen source, a pellet of LiAlH 4 was used. In our previous experiment [11] we used a mixture of NaBH 4 + 2Ca(OH) 2 . When heated these materials decompose irreversibly at about 300 • C and supply H 2 to the sample.…”

“…We recently reported [11] in situ synchrotron X-ray experiments on Mg 2 NiH 4 at hydrogen pressures up to 5.6 GPa and 600 • C and the purpose of this paper is to report in detail on the structural changes with an aim to provide definite answers to the nature of the HP phase transitions.…”

Effect of stoichiometry on hydrogen storage performance of Ti–Cr–VFe based alloys

“…LaNi 5 based alloys are usually categorized as the first generation hydrogen storage alloy and have been massively applied to Ni-MH rechargeable batteries [1]. TiFe and TiMn based alloys are taken for the second generation [2][3][4][5]. TiCr and Mg based alloys are considered as the third generation [6][7][8].…”