The self‐diffusion coefficient of oxygen in (polished slices of a Verneuil) single‐crystal alumina was determined in the temperature range 1500–1770 °C by means of the gas–solid isotope exchange technique. The results were represented by D=1.12×103 exp (−155×103/RT) cm2/s. The activation energy was interpreted to be for intrinsic diffusion. By comparison of the results with the oxygen self‐diffusion coefficients previously reported for crushed particles of a Verneuil alumina and a vapor‐grown alumina, the extrinsic diffusion exhibited by the crushed particles was confirmed to be due to a dislocation enhancement process.

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© 1980 American Institute of Physics.
1980
American Institute of Physics
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