Abstract
The influence of structural vacancies in metal and non-metal sublattices on the electronic structure of titanium carbide and oxide is studied by the nonempirical Hartree-Fock-Slater method in the cluster approximation. The main valence band changes for non-stoichiometric compounds are connected with the narrowing of bands due to subtraction of a number of electronic states and an increase of density of states near the Fermi level. Vacancy states appear to be localized in the unoccupied region of the energy spectrum; their admixture in the valence band is very small. The valency of metal atoms is shown to vary continuously in accordance with the stoichiometry ratio. The vacancy charge is very much smaller than the formal ionicity of the atom removed. It is shown that in defect compounds there is essentially no bonding charge connected with the vacancy center. The results obtained are compared with the data of previous calculations and physico-chemical properties.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 719-730 |
| Number of pages | 12 |
| Journal | Journal of Physics and Chemistry of Solids |
| Volume | 45 |
| Issue number | 7 |
| DOIs | |
| State | Published - 1984 |
Funding
Acknowledgements--This work was supported in part by the U.S. National Academy of Sciences under the auspices of the NASjUSSR Academy of Sciences exchange program, and by the US ARO, Contract No. DAA29-80-C0035. We thank F. W. Kutzler for helpful discussions and access to unpublished data. Use of facilities of the Northwestern University Materials Research Center is gratefully acknowledged.
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics