Hydrogen-induced phase decomposition of Ca_8Al_3 intermetallic compound

摘要

The pure Ca_8Al_3 intermetallic compound was prepared by induction melting of appropriate amounts of pure metals and subsequent annealing. Furthermore, the hydrogenation behavior of the Ca_8Al_3 compound was studied in detail. It was found that the Ca_8Al_3 compound can react with hydrogen to form CaH_2 and Al starting from 373 K, but the process is very sluggish at a low temperature. Prior to the decomposition, the lattice parameters of Ca_8Al_3 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 Ca_8Al_3 occurs entirely.