Hydrogen Donors and Ti3+ ions in reduced TiO2 crystals
Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify and characterize the neutral hydrogen donor in TiO2 crystals having the rutile structure. These spectra are best observed near 5 K. The neutral donors are present without photoexcitation in crystals that have been slightly reduced at high temperature in a nitrogen atmosphere. The same defects can be photoinduced at low temperature in oxidized crystals. The neutral hydrogen donor in this lattice consists of a substitutional Ti3+ ion adjacent to a substitutional OH– molecular ion. The axis of the OH– molecule lies in the basal plane with the hydrogen ion extending out from the oxygen in a direction perpendicular to the Ti-O bonds. Spin-Hamiltonian parameters are obtained from the angular dependence of the EPR and ENDOR spectra (principal values are 1.9732, 1.9765, and 1.9405 for the g matrix and –0.401, + 0.616, and –0.338 MHz for the 1H hyperfine matrix). The principal axis associated with the + 0.616 MHz principal value is in the basal plane 22.9° from a  direction and the principal axis associated with the –0.338 MHz principal value is along the  direction. Our results show that interstitial Ti3+ ions are not the dominant shallow donors in slightly reduced TiO2 (rutile) crystals.
Journal of Applied Physics
Brant, A. T., Giles, N. C., & Halliburton, L. E. (2011). Hydrogen donors and Ti 3+ ions in reduced TiO 2 crystals. Journal of Applied Physics, 110(5), 053714. https://doi.org/10.1063/1.3630964
The "Link to Full Text" on this page opens the full article [HTML] with expandable figures, hosted at AIP Publishing. A PDF of the published article is available at the top of that page.
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in volume 110 of Journal of Applied Physics as cited and linked below.
Plain-text title: Hydrogen Donors and Ti(3+) ions in reduced TiO(2) crystals