A combination of metadynamics and kinetic Monte Carlo simulation approaches was applied to the investigation of oxygen vacancy diffusion in alumina. Three classes of diffusive jumps with different activation energies were identified, the resulting diffusion coefficient being best fitted by an Arrhenius equation having a pre-exponential factor of 7.88 x 10-2m2/s and an activation energy of 510.83kJ/mol. This activation energy was very close to values for the most pure aluminas studied experimentally (activation energy 531kJ/mol). The good agreement indicated that the dominating atomic-scale diffusion mechanism in alumina was vacancy diffusion.

Oxygen Vacancy Diffusion in Alumina: New Atomistic Simulation Methods Applied to an Old Problem. U.Aschauer, P.Bowen, S.C.Parker: Acta Materialia, 2009, 57[16], 4765-72