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篇目详细内容 |
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【篇名】 |
Oxygen-ion diffusion and electrical conduction of La2Mo2-xFexO9-未 systems |
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【刊名】 |
Frontiers of Materials Science in China |
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【刊名缩写】 |
Front. Mater. Sci. China |
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【ISSN】 |
1673-7377 |
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【EISSN】 |
1673-7482 |
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【DOI】 |
10.1007/s11706-008-0008-6 |
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【出版社】 |
Higher Education Press and Springer-Verlag |
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【出版年】 |
2008 |
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【卷期】 |
2
卷1期 |
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【页码】 |
42-47
页,共
6
页 |
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【作者】 |
LI Chun;
FANG Qian-feng;
WANG Xian-ping;
ZHANG Guo-guang;
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【关键词】 |
oxide-ion conductor; La2Mo2O9; dielectric relaxation (DR); phase transition |
【摘要】 |
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Based on the novel oxygen ion conductor La2Mo2O9, a series of Fe-doped samples of La2Mo2-xFexO9-δ (x = 0, 0.025, 0.05, 0.1) was prepared by conventional solid-state reaction method. The structure, phase transition, oxygen ion diffusion and electrical conductivity were studied with X-ray diffraction (XRD), differential scanning calorimeter (DSC), direct current (dc) resistivity, and dielectric relaxation (DR) measurements. One DR peak associated with the short-distance diffusion of oxygen vacancies was observed in both temperature and frequency spectra. The activation energy for oxygen ion diffusion in Fe-doped La2Mo2O9 samples was smaller than that in un-doped samples. Fe doping can increase the ionic conductivity of La2Mo2-xFexO9-δ samples as well as the ionic transference number in the temperature range from 680°C to 400°C in comparison with the un-doped samples, although the electronic conductivity slightly increases. It is found that because of the small solubility of Fe2O3 in La2Mo2O9 (<5%), Fe doping cannot suppress the phase transition that occurred around 570°C, but 2.5% K doping at La site at the same time (e.g. in sample La1.95K0.05Mo1.95Fe0.05O9-δ) can completely suppress this phase transition and increase conductivity at lower temperatures. |
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