Structural and hydrogen storage properties of LaCaMgNi9-type alloy obtained by mechanical alloying

Abstract

The AB 3 -type LaCaMgNi 9 compound was synthesized using mechanical alloying (MA) starting from elemental La, Ca, Mg, and Ni in the atomic ratio 1:1:1:9. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to study the phase evolution and formation/kinetic mechanism as a function of milling time (4-30 h). The results show multiphase alloys containing LaCaMgNi 9 as a main phase with trigonal PuNi 3 -type structure (R-3m space group) where Ca atoms occupy preferentially the 3a site, while La and Mg atoms occupy the 6c site with a mean composition CaLa 1.2(2) Mg 0.8(2) Ni 9 . The hydrogenation properties of the alloys were examined by solid-gas reaction at room temperature. The PCI curves showed a plateau pressure of 0.25 bar which corresponds to the AB 3 phase. The hydrogen absorption capacity of the AB 3 phase is equal to 5.6 H/u.f AB3 .

Effect of Al presence and synthesis method on phase composition of the hydrogen absorbing La–Mg–Ni-based compounds

“…spark plasma sintering, melt spinning) have also been applied [32,33]. Ball milling was reported to enable facilitate formation of compounds with A2B7and AB3-type structures [22,34]. This is a well-recognized technique, used for synthesis of a great variety of compositions for energy conversion and storage,.…”

Intermetallic Compounds Synthesized by Mechanical Alloying for Solid-State Hydrogen Storage: A Review

“…The use of mechanical alloying (MA) can avoid these difficulties. S. Chebab et al [111] used MA to treat pure La, Ni, Ca, and Mg powders for 30 hours, and the weight percent of this phase reached 67 %. This alloy can absorb 6 H/f.u.…”

Synthesis of quaternary nano‐intermetallic LaTi 2 Ni 5 Al 4 with its hydrogen encapsulation and inspection using lithium‐hydride cell

“…Recently in our research-team framework, we are more interested and involved in AB 3 -intermetallics materials [14][15][16][17][18][19][20][21][22] obtained using binary AB 2 and AB 5 precursors alongside their solid-gas hydrogen reaction.…”