Self-diffusion was measured in single crystals of the -phase, at 1540 to 1697C, by using 26Al as a radiotracer. It was found that 2 diffusion mechanisms were involved. These were a lattice diffusion mechanism and a sub-boundary mechanism. The former could be described by:

D (cm2/s) = 1.6 x 10-1 exp[-121(kcal/mol)/RT]

The results showed that the lattice diffusion coefficients of Al were much lower than those previously reported. The O and Al diffusion coefficients were of the same order of magnitude in the lattice.

M.Le Gall, B.Lesage, J.Bernardini: Philosophical Magazine A, 1994, 70[5], 761-73