Electron-beam-induced transition aluminas from aluminum trihydroxide

Transition aluminas induced by electron-beam irradiation from an aluminum trihydroxide were quantitatively investigated. After the transition of an aluminum trihydroxide initiated at a threshold value of an electron dose, the advent of the major phase in each transition step depended on the total electron dose. The transition process can be categorized into a three-stage transition: (A) rapid dehydration (χ-alumina) → (B) gradual dehydration (γ-alumina) → (C) nanocrystallization (γ- and σ-alumina).