Electron-beam-induced transition aluminas from aluminum trihydroxide

Abstract

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 (chi-alumina) -> (B) gradual dehydration (gamma-alumina) -> (C) nanocrystallization (gamma- and sigma-alumina). (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.