Investigating the impact of yttria doping on radiation-induced crystallization in alumina

Amorphous alumina coatings grown by Pulsed Laser Deposition are considered a promising solution for the commercialization of heavy liquid metal Fast Fission reactor as well as Fusion Reactor. These coatings offer corrosion protection of the structural steels from molten lead as well exceptional tritium permeation reduction properties and electrical insulation. The amorphous to crystalline transition of these coatings has been studied in recent years highlighting the drawbacks of crystallization under operating conditions of the reactor core, where temperatures can easily rise above 600 °C, temperature of crystallization of pure PLD alumina, and intense radiation field can have destructive effect on the film’s integrity. In the present work, Y 2 O 3 doping has been evaluated as a strategy to extend the stability of the metastable amorphous phase of alumina. Heavy ion irradiation experiments were carried out with dynamic observation at the Intermediate Voltage Electron Microscope (IVEM)-Tandem Facility, at Argonne National Laboratory, in order to observe the radiation induced crystallization of 3 % Y 2 O 3 -Doped Al 2 O 3 . Findings show a stabilizing effect of yttrium oxide onto the amorphous phase of alumina, successfully delaying radiation induced crystallization of the material towards higher temperatures and higher radiation doses, thus extending its possible operational lifetime.