The cation lattice diffusion coefficient in yttria-stabilized material was deduced from a comparison, with deformation theories, of high-temperature deformation data on monocrystals and polycrystals having various grain sizes and yttria contents. It was confirmed that lattice diffusion was the ultimate strain rate-controlling process. It was found that the absolute magnitude of the diffusion coefficient which was estimated in this way was in excellent agreement with the published results of diffusion studies; but with an activation energy of 550kJ/mol. This was about 100kJ/mol higher than previously reported values.

M.Jiménez-Melendo, A.Domínguez-Rodríguez, D.Gómez-García, A.Bravo-León, J.Martínez-Fernández: Materials Science Forum, 1997, 239-241, 61-4