Damage structures were studied, using cross-sectional electron microscopy, in a single crystal which had been simultaneously bombarded at 923K with H-, He- and O- ions having energies of 0.25, 0.9 and 4.7MeV, respectively, to fluences of 2.7 x 1020, 3.5 x 1020 and 5.5 x 1020/m2. High densities of dislocation loops were formed to a depth of 2.4μm, and the loop density increased with increasing depth. Cavities were observed in bands, and the swelling peaked at depths of 1.4, 1.9 and 2.3μm for H-, He- and O- ion-implanted regions, respectively.

Damage Structure Evolution in Al2O3 Irradiated with Multiple Ion Beams of H, He and O and After Annealing. Y.Katano, T.Nakazawa, D.Yamaki, T.Aruga, K.Noda: Journal of Nuclear Materials, 1998, 258-263, 1842-7