The diffusion of interstitial Ti3+ species (Tii3+) in rutile TiO2(110) from the bulk to the surface was studied using two experimental techniques. Electron-stimulated desorption of O+ ions was used to kinetically monitor the reaction between oxygen adatoms with Tii3+ species at between 360 and 400K. Scanning tunnelling microscopy was also used to measure the Tii3+ diffusion rate. Both methods yielded a rate constant of 5 x 10-4/s at 393K. The activation energy as measured via the rate dependence upon temperature was about 1.0eV.

Unraveling the Diffusion of Bulk Ti Interstitials in Rutile TiO2(110) by Monitoring their Reaction with O Adatoms. Zhang, Z., Lee, J., Yates, J.T., Bechstein, R., Lira, E., Hansen, J.Ø., Wendt, S., Besenbacher, F.: Journal of Physical Chemistry C, 2010, 114[7], 3059-62