Microstructure of A12O3 Irradiated with an Applied Electric Field

Abstract

AbstractA thin amorphous film of alumina was irradiated with 2-MeV He+ ions at ~400°C up to a damage level of about 0.01 displacements per atom (dpa). The alumina films were sufficiently thin (~1.8 μm) to allow the ion beam to be completely transmitted through the specimen. An electric field of μ280 V/;mm (dc) was applied continuously during the irradiation. Radiation induced electrical degradation (RIED), i.e. a permanent increase in the conductance of the film, was observed in specimens irradiated at temperatures near 400 to 450°C but did not occur in a specimen irradiated above 500°C. An investigation by transmission electron microscopy found no evidence for colloid formation. The observed increase in the conductance of the alumina film may be due to radiation-induced microcracking.