An ab initio study of oxygen vacancies and doping process of Nb and Cr atoms on TiO2 (110) surface models
✍ Scribed by J. R. Sambrano; J. Andrés; A. Beltrán; F. R. Sensato; E. R. Leite; F. M. L. G. Stamato; E. Longo
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 193 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
✦ Synopsis
We theoretically investigated how the formation of oxygen vacancies and the addition of niobium and chromium atoms as dopants modify the varistor properties of TiO . The calculations were carried out at the HF level using a contracted 2 Ž . basis set, developed by Huzinaga et al., to represent the atomic centers on the 110 Ž . surface for the large TiO cluster model. The change of the values for the net atomic 2 15
charges and band gap after oxygen vacancy formation and the presence of dopants in the lattice are analyzed and discussed. It is shown that the formation of oxygen vacancies decreases the band gap while an opposite effect is found when dopants are located in the reduced surface. The theoretical results are compared with available experimental data. A plausible explanation of the varistor behavior of this system is proposed.