Evolution of microstructure characteristics during the electron-beam-induced phase transition of aluminum trihydroxide

We report interesting microscopic features that evolve as a function of electron dose from the starting aluminum trihydroxide to the resulting transition aluminas with layered mesoporous structures. Remarkably, the sizes of pores and crystals in the porous structure were reduced as the electron dose was increased. The properties of the layered structure from the aluminum trihydroxide were maintained through the transition process, and hence the final mesoporous structures (mainly γ-alumina) were of lamella-type microstructure.