First measurements of oxygen grain boundary diffusion coefficients in nanocrystalline yttria-doped ZrO2 (n-ZrO2·6.9mol%Y2O3) were presented. The 18O diffusion profiles measured by secondary ion mass spectroscopy were much deeper in the nanocrystalline specimens than in single crystals. An oxygen diffusivity, DB, in the grain boundaries can be deduced, which was ≈3 orders of magnitude higher than in single crystals. From the present data the temperature variation of the oxygen grain boundary diffusivity,

D(m2/s) = 2.0 x 10-5 exp[-0.91(eV)/kT]

were derived.

G.Knöner, K.Reimann, R.Röwer, U.Södervall, H.E.Schaefer: Proceedings of the National Academy of Sciences, 2003, 100[7], 3870-3