ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The sintering of TiO2 has been studied with respect to oxygen partial pressure ( $$P_{O_{\text{2}} }$$ ) and doping content. From the microstructural evolution, it is obvious that a decrease of the oxygen pressure promotes the densification with a comparatively smaller grain growth than in air sintering. This fact has been related with the influence of defects on the sintering. Both effects of $$P_{O_{\text{2}} }$$ and tantalum doping have been studied. They are interpreted on the basis of a model involving interstitial titanium, electron holes, titanium vacancies and complexes associating titanium vacancies with tantalum substituted titanium. This latter complex is probable according to previous microscopic studies of defects in TiO2−x and may be important in highly doped compounds. The formation of such associates reduces the mobile defect concentration, however a decrease of the $$P_{O_{\text{2}} }$$ favour their dissociation. The titanium vacancies which are thus released allow the titanium ions to migrate, a necessary condition for the sintering.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00551958
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