This work determines the self-diffusion coefficients of indium in TiO2 single crystal (rutile). Diffusion concentration profiles were imposed by deposition of a thin surface layer of InCl3 on the TiO2 single crystal and subsequent annealing at 1073 to 1573K. The diffusion-induced concentration profiles of indium as a function of depth were determined by using secondary ion mass spectrometry. These diffusion profiles were used to calculate the self-diffusion coefficients of indium in the polycrystalline In2TiO5 surface layer and the TiO2 single crystal. The temperature dependence of the latter diffusion coefficients, in the range 1073-1573K, could be expressed by:

D (m2/s) = 7.4 x 10-4exp[-316(kJ/mol)/RT]

The obtained activation energy for bulk diffusion of indium in rutile (316kJ/mol) was similar to that of zirconium in rutile (325kJ/mol).

Diffusion Kinetics of Indium in TiO2 (Rutile). Atanacio, A.J., Bak, T., Nowotny, J., Prince, K.E.: Journal of the American Ceramic Society, 2013, 96[5], 1366-71