Density functional calculations of O incorporation and diffusion in monoclinic hafnia were performed for a range of O charge states. The calculations demonstrated that O favored atomic incorporation, and that O2– was the most stable species. It was found that O interstitials diffused via exchange with lattice O sites in hafnia, and that O– species had the smallest diffusion barrier.

Mechanism of Interstitial Oxygen Diffusion in Hafnia. A.S.Foster, A.L.Shluger, R.M.Nieminen: Physical Review Letters, 2002, 89[22], 225901 (4pp)