On Oxygen Diffusion in tetragonal zirconia

Oxygen diffusion in dense scales of tetragonal zirconia at 1100–1300°C has been studied by the so‐called interruption kinetic method (or the Rosenberg method). Assuming that oxygen vacancies are the predominant defects in zirconia (ZrO 2 ), studies by this method provide values of the oxygen self diffusion coefficient in this oxide at its lower limit of stability, D   0 * , and the value in tetragonal zirconia can be expressed as D   0 *=2.2 · 10 −3 exp (−140(kJ/mole)/RT). The studies furthermore show that the maximum non‐stoichiometry in tetragonal zirconia, X in ZrO 2−x , is small and has a value about x* ∼ 0.03 at 1000–1300°C.