Self-diffusion was measured in single crystals of -phase yttria-doped material, at 1110 to 1630C, using 18O2 and secondary ion mass spectrometry. At lower temperatures, only bulk diffusion was observed. It was shown that the bulk diffusion data could be described by:

D (cm2/s) = 6.7 x 101 exp[-141(kcal/mol)/RT]

It was concluded that an extrinsic diffusion mechanism which involved O interstitials or defect complexes could explain the results for bulk undoped material.

M.Le Gall, A.M.Huntz, B.Lesage, C.Monty: Philosophical Magazine A, 1996, 73[4], 919-34

The best linear fits to the solute diffusion data ([430] to [437]) yield:

O: Ln[Do] = 0.20E – 24.5 (R2 = 0.99); O(gb): Ln[Do] = 0.37E – 45.4 (R2 = 0.96)