The diffusion of Y in the α-phase of alumina was measured, at 1150 to 1500C, by means of secondary ion mass spectrometry. It was found that the diffusion data could be described by:

D (cm2/s) = 1.2 x 10-6 exp[-70.2(kcal/mol)/RT]

These results were similar to those for Cr diffusion in this material, although the Y3+ ion was much larger than the Cr3+ ion.

E.G.Moya, F.Moya, B.Lesage, M.K.Loudjani, C.Grattepain: Journal of the European Ceramic Society, 1998, 18[6], 591-4