Oxygen Exchange and Diffusion in Calcia‐Stabilized Zirconia

Oxygen diffusion was measured by the sectioning technique on single‐crystal and polycrystalline specimens of Zr 0.858 Ca 0.142 CO 1.858 . The diffusion coefficient, which may be represented by the equation D = 0.01818 +0.068 ‐0.015 exp ‐ (31, 200 × 4300)/ RT cm 2 /sec agrees with that calculated from the electrical conductivity and an oxygen transport number of 1. The oxygen surface exchange coefficient may be represented by α= 0.078 +0.443 ‐0.066 exp ‐ (22,800 × 4400/ RT cm/sec The quantitative influence of ignoring the exchange rate on the apparent diffusion coefficient is discussed.