A study of the diffusion of titanium ions was performed by diffusing 44Ti radio-isotope into single-crystal rutile at 900 to 1300C (table 13). The data were found to be described by:

D (cm2/s) = 6.4 x 10-2exp[-61.4(kcal/mol)/RT]

From an analysis of the magnitude of the frequency factor and from a comparison with values for the self-diffusion coefficient of tin in tin oxide, it was concluded that the activation energy represented the migration energy of the cation. Additional support for this conclusion was found from data on creep in rutile. The close agreement between the Do and E values for titanium and oxygen diffusion in rutile suggested similar diffusion paths. The possibility of cooperation of both anion and cation defects in the diffusion of either species was considered.

Diffusion of Titanium in Single Crystal Rutile. Venkatu, D.A., Poteat, L.E.: Materials Science and Engineering, 1970, 5[5], 258–62

Table 13

Self-diffusion of Ti in monocrystalline TiO2