Tracer diffusion coefficients of Fe in single crystals of rutile and of 0 to 2.0%Fe-doped rutile were measured. The oxygen pressure dependence of DFe in pure rutile exhibited a complicated behavior. Complex impedance measurements of electrical conductivity indicated the existence of ionic conduction for Fe-doped rutile containing less than 0.35%Fe. The small ionic conductivity relative to the values of DFe suggested that only a small fraction of the iron ions were highly mobile. Above 0.35%Fe, the observed drastic decrease in DFe might result from the formation of a shear structure in highly doped rutile.

Fast Diffusion of Iron in Single Crystal Rutile and Iron Doped Rutile. Sasaki, J., Peterson, N.L., De Jonghe, L.C.: Materials Research Society Symposia Proceedings, 1984, 24, 39-45