Ionization-induced effects in amorphous apatite at elevated temperatures

Journal Article
Journal of Materials Research, vol. 23, iss. 4, pp. 962-967, 2011
Authors
In-Tae Bae, Yanwen Zhang, William J. Weber, Manabu Ishimaru, Yoshihiko Hirotsu, Mikio Higuchi
Abstract
Electron-beam-induced effects in preamorphized Sr2Nd8(SiO4)6O2 were investigated in situ using transmission electron microscopy with 200-keV electrons at temperatures ranging from 380 to 780 K. Within the electron-irradiated area, epitaxial recrystallization was observed from the amorphous/crystalline interface toward the surface, with the rate of recrystallization increasing as temperature increased from 380 to 580 K. Structural contrast features (i.e., O deficient amorphous material), as well as recrystallization, were observed outside of the irradiation area at temperatures from 680 to 780 K. Ionization-induced processes and local nonstoichiometry induced by oxygen migration and desorption are possible mechanisms for the electron-beam- induced recrystallization and for the formation of the structural contrast features, respectively.
English