Hydrogen-induced phase decomposition of Ca8Al3 intermetallic compound

The pure Ca8Al3 intermetallic compound was prepared by induction melting of appropriate amounts of pure metals and subsequent annealing. Furthermore, the hydrogenation behavior of the Ca8Al3 compound was studied in detail. It was found that the Ca8Al3 compound can react with hydrogen to form CaH2 and Al starting from 373 K, but the process is very sluggish at a low temperature. Prior to the decomposition, the lattice parameters of Ca8Al3 do not change, indicating that the compound does not absorb hydrogen to form solid solution. Increasing hydrogenation temperature to 523 K, the hydrogen-induced decomposition of Ca8Al3 occurs entirely.