Document Type
Article
Publication Date
9-2013
Abstract
Results from electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) experiments are used to establish the model for the ground state of the singly ionized oxygen vacancy in the interior of bulk rutile TiO2 crystals. Hyperfine from 47Ti and 49Ti nuclei show that the unpaired electron in this S = 1/2 defect is localized on one titanium ion adjacent to the oxygen vacancy (i.e., the spin is not shared by two titanium ions). These defects are formed at low temperature (∼35 K) in as-grown oxidized crystals when sub-band-gap 442 nm laser light converts doubly ionized nonparamagnetic oxygen vacancies to the singly ionized paramagnetic charge state. The g matrix is obtained from EPR spectra and the 47Ti and 49Ti hyperfine and nuclear electric quadrupole matrices (A and Q) are obtained from ENDOR spectra. Principal values of the 47Ti and 49Ti hyperfine matrices are 64.54, 11.57, and 33.34 MHz. All the matrices have a principal axis along the [001] direction. In the basal plane, principal axes of the hyperfine and quadrupole matrices also coincide. The principal axes of the g matrix in the basal plane, however, deviate significantly from those of the A and Q matrices, thus indicating mixing of d orbitals due to the low symmetry at the Ti3+ ion site and participation of excited-state orbitals.
Source Publication
Journal of Applied Physics
Recommended Citation
Brant, A. T., et al. (2013). Ground state of the singly ionized oxygen vacancy in rutile TiO2. Journal of Applied Physics, 114(11),113702. https://doi.org/10.1063/1.4819805
Comments
© 2013 AIP Publishing LLC, published under an exclusive license with American Institute of Physics.
AFIT Scholar, as the repository of the Air Force Institute of Technology, furnishes the published Version of Record for this article in accordance with the sharing policy of the publisher, AIP Publishing. A 12-month embargo was observed.
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 Journal of Applied Physics, 114:113702 as fully cited below and may be found at 10.1063/1.4819805.