Anion diffusion was simulated, in the (Y0.2Zr0.8)-(O1.72N0.15) system, by using molecular dynamics techniques and empirical potentials of Buckingham type. In order to describe N migration, N potentials had to be developed by assuming interaction of the charged N shells with a mass of 0.15amu. Upon comparing the experimental and simulated anion diffusivities, the diffusion coefficients were found to be of similar order. However, N diffused 5 times slower than O, according to the computer simulation. On the other hand, the experimentally measured difference was reported to be smaller. The calculated activation enthalpies were 1.2 and 1.4eV, respectively, for these 2 elements; with pre-exponential factors of 10-5 and 10-4cm2/s, respectively.

Molecular Dynamics Calculations of Anion Diffusion in Nitrogen-Doped Yttria-Stabilized Zirconia. M.Kilo, T.Homann, T.Bredow: Philosophical Magazine, 2007, 87[6], 843-52