Deuterium site occupancies in Ce2Ni7D∼4 and comparison with CeNi3D2.8

Effects of annealing and stoichiometry to (Nd, Mg)(Ni, Al)3.5 metal hydride alloys

“…Due to the different directions for the proton to transport in AB 2 (along c-axis) and AB 5 (along aeb plane) MH alloys [41,42], the former prefers a smaller while the later prefers a larger c/a ratio to decrease the pulverization during hydriding/dehydriding cycles [43,44]. The Nd 2 Ni 7 structure is the stacking of AB 5 and 2 Â AB 2 units, and the preferential sites for deuterium are all in the AB 2 slabs according to the XRD study [45,46]. Consequently, the protons will likely hop along the aeb plane as in the case of AB 5 MH alloy.…”

Crystal structure of GdNi3 with superlattice alloy and its hydrogen absorption–desorption property

“…The GdNi 5 cell expanded by 2.15%, but the Gd 2 Ni 4 cell shrank by 2.83% from the original alloy. The behaviors of CaCu 5 -and MgZn 2 -type cells in Gd 2 Ni 7 differed from that of La 2 Ni 7 [15] and Ce 2 Ni 7 [16,17]. The MgZn 2 -type cells of La 2 Ni 7 and Ce 2 Ni 7 expanded by over 50%, and the CaCu 5 -ype cell shrank slightly after deuteration.…”

Hydrogenation of AB5 and AB2 metal hydride alloys studied by in situ X-ray diffraction

“…In order to further improve the hydrogen storage and cycle performance of these MH alloys, the understanding of hydrogen distribution during hydrogenation is very critical among all the decisive prerequisites. The crystal structures of the basic binary/pseudo-binary MH, such as LaNi 5 [29], (Lu 0.4 Y 0.6 )Mn 2 [30], La 2 Ni 7 [31], Ce 2 Ni 7 [32], (La,Mg) 2 Ni 7 [33], Ti(Ni, Cu) [34], Sm 2 Co 7 [35], and YMgCo [36], are thoroughly studied. For example, Pan et al [37] reported a metal hydride composed of a C14 Laves phase and a solid solution phase, in which the C14 Laves phase had good surface electrochemical activity for decomposing water when charging.…”