Influence of an electric field on the microstructure evolution of ion-irradiated alumina

Radiation-induced defects in α-alumina were investigated through transmission electron microscopy for specimens irradiated with 100 keV He+ ions at 760 K with an electric field of 100 kV/m. Ion-irradiation with an electric field induces characteristic defect clusters, such as bundles of long-shaped defect clusters, aluminum colloid and γ-alumina precipitates, and interstitial type-dislocation loops, though only dislocation loops were formed when the material is irradiated without an electric field. Electron microscopy analysis has revealed the lattice displacement vector of long-shaped defects, and the crystallographic relationship among α-alumina matrix, aluminum colloid and γ-alumina.