Electronic structure of the ion pair model for Ti:Al<sub>2</sub>O<sub>3</sub>
F X Zha; J H Zhang; S D Xia; F X Zha; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; J H Zhang; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; S D Xia; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1994-08-08
Аннотация:
The Ti<sup>3+</sup>-Ti<sup>4+</sup> ion pair is proposed experimentally to be responsible for the infrared residual absorption of Ti:Al<sub>2</sub>O<sub>3</sub>. However, no theoretical verification has been presented to date. In this paper, the DV-X<sub>alpha </sub> calculation is performed upon clusters of (Ti<sup>3+</sup>O<sub>6</sub><sup>2-</sup>)<sup>9-</sup>, (Ti<sup>3+</sup>Al<sup>3+</sup>O<sub>9</sub><sup>2-</sup>)<sup>12-</sup> and (Ti<sup>3+</sup>Ti<sup>4+</sup>O<sub>9</sub><sup>2-</sup>)<sup>11-</sup>. Our work not only has interpreted the infrared residual absorption but also has clarified the confusion about the origin of the ultraviolet absorptions. Therefore the Ti<sup>3+</sup>-Ti<sup>4+</sup> pair postulation is strongly supported by our present work.
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