Stoichiometry deviation in amorphous zirconium dioxide

Amorphous zirconia (a-ZrO 2 ) has been simulated using a synergistic combination of state-of-the-art methods: employing reverse Monte-Carlo, molecular dynamics and density functional theory together. This combination has enabled the complex chemistry of the amorphous system to be efficiently investigated. Notably, the a-ZrO 2 system was observed to accommodate excess oxygen readily - through the formation of neutral peroxide (O 2 2− ) defects - a result that has implications not only in the a-ZrO 2 system, but also in other systems employing network formers, intermediates and modifiers. The structure of the a-ZrO 2 system was also determined to have edge-sharing characteristics similar to structures reported in the amorphous TeO 2 system and other chalcogenide-containing glasses. The accommodation mechanism for excess oxygen in amorphous ZrO 2 is identified using state-of-the-art methods: employing reverse Monte-Carlo, molecular dynamics and density functional theory together. Excess oxygen is predicted to enter amorphous ZrO 2 exothermically from O 2 .