Substitution effects of rare earth elements for hydrogenation of MmNi 3.55Co0.75Al0.30Mn0.40 AB 5-type alloys were investigated, where Mm consisted of La-Pr-Nd-M (M: Ce, Y, Gd, Tm and Lu), and the amount of La and M was adjusted to keep the lattice volume identical which leads to a similar equilibrium hydrogen pressure. The above alloys showed two-phase reaction during hydrogenation, and both the phases had the orthorhombic lattice with a space group of Cmmm after activation. The Ce containing alloy showed a higher equilibrium hydrogen pressure (0.12 MPa) than the others (0.07-0.10 MPa) at 298 K. In addition, this alloy showed the largest lattice volume expansion among the alloys investigated. However, lattice strain of the hydride phases calculated from line broadening in X-ray diffraction peaks showed to be less than 0.9% for all the alloys investigated.
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering