Formation and crystal growth process of AlH in Al-H system

Saito, Hiroyuki; Okajima, Yuka; Yoneda, Yasuhiro   ; Machida, Akihiko; Kawana, Daichi; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi

The hydrogenation process of aluminum is observed at high pressure and temperature by angle-dispersive X-ray diffraction method. At 10 GPa and 600 C, single crystals of AlH about 20 m in size are found to grow through three steps: self-pulverization of aluminum, hydrogenation of pulverized aluminum, and solid-state grain growth of hydride. The self-pulverization seems to be the precursor of the hydrogenation reaction because it occurs at pressure temperature conditions where AlH is thermodynamically stable.