ISSN:
0020-7608
Keywords:
ab initio
;
oxygen vacancy
;
doping
;
titanium oxide surface
;
varistor ceramics
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
We theoretically investigated how the formation of oxygen vacancies and the addition of niobium and chromium atoms as dopants modify the varistor properties of TiO2. The calculations were carried out at the HF level using a contracted basis set, developed by Huzinaga et al., to represent the atomic centers on the (110) surface for the large (TiO2)15 cluster model. The change of the values for the net atomic 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. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65: 625-631, 1997
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
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