Surface-based manipulation of point defects in rutile TiO2

Through isotopic self-diffusion measurements, the present work resolves a discrepancy in the literature about the primary oxygen-related point defect in rutile TiO2 by showing that suitably prepared surfaces can controllably inject large numbers of an exceptionally mobile defect. Results strongly suggest that this defect is the oxygen interstitial, whose existence in TiO2 has been predicted computationally but never experimentally confirmed. The surface pathway offers an approach for replacing donor oxygen vacancies with acceptor oxygen interstitials facilitating manipulation of near-surface electronic bands. (C) 2013 AIP Publishing LLC.