Mutual diffusion coefficients in the Al2O3/Cr2O3 system were determined in air, at temperatures of between 1676 and 1793K, by using a couple technique. The couples consisted of single crystals of alumina which were embedded in chromia powder, and the penetration curves were obtained by means of electron-probe micro-analysis. The results could be expressed by:

D (m2/s) = 1.78 x 10-5 exp[-435(kJ)/RT]

The mutual diffusion coefficients increased exponentially with increasing chromia concentration.

K.Atarashiya, R.Nagasaki, K.Nishida: Journal of the Japan Institute of Metals, 1987, 51[11], 1018-22