It was found that the data O diffusion in polycrystalline and monocrystalline material, at 800 to 1200C, could be described by:

monocrystalline:     D (cm2/s) = 7.9 x 104 exp[-73.9(kcal/g-atom)/RT]

polycrystalline:     D (cm2/s) = 9.5 x 104 exp[-74.4(kcal/g-atom)/RT]

R.Barlow, P.J.Grundy: Journal of Materials Science, 1969, 4[9], 797-801