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摘要
Ce0.9Gd0.1O2-delta powder was prepared by oxalate coprecipitation. Fe2O3 (0.5 at.%) was loaded into the powder through two approaches-mechanical mixing and wet chemical loading. The densification behavior, microstructure and electrical properties of the unloaded and Fe-loaded Ce0.9Gd0.1O2-delta ceramics, sintered at temperatures ranging from 1000 to 1550 degreesC for 5 h, were investigated. Both the Fe loading and the loading method exhibited a remarkable effect on the densification of Ce0.9Gd0.1O2-delta ceramics. The Fe loading by chemical way was more effective in promoting densification in the temperature range less than 1300 degreesC, as compared to that by mechanical mixing. However, the two different ways for Fe loading led to a very similar way in affecting the grain boundary (GB) conduction of the Ce0.9Gd0.1O2-delta ceramics. The GB conductance of the Fe-doped Ce0.9Gd0.1O2-delta ceramics experienced a rapid increase from 1100 to 1250 degreesC, reached a relatively broad maximum over 1250-1500 degreesC, and finally decreased at >1500 degreesC. This was completely different from the variation in the GB conduction of the unloaded samples with temperature, which decreased consistently with increasing sintering temperature. The Fe2O3 dopant exhibited the optimal scavenging effect in the temperature range of 1250-1500 degreesC, in which a higher total conductivity and a lower activation energy for the total conduction were achieved for Ce0.9Gd0.1O2-delta ceramics. Finally, the possible mechanisms related to the enhanced densification behavior and the improved GB conduction of the Ce0.9Gd0.1O2-delta ceramics due to Fe loading were discussed.
- 出版日期2005-1-31
- 单位南阳理工学院
