Structural, thermomechanical and electrical properties of new (1 − x)Ce0.8Nd0.2O2−δ–xBaCe0.8Nd0.2O3−δ composites
| Autor: | B. Antonov, E. Pikalova, A. Podias, Dmitry Medvedev, I. Korzun, Panagiotis Tsiakaras, Anatoly Demin |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Energy Engineering and Power Technology Partial pressure Conductivity Grain size Thermal expansion law.invention law visual_art visual_art.visual_art_medium Ionic conductivity Calcination Ceramic Electrical and Electronic Engineering Physical and Theoretical Chemistry Composite material Perovskite (structure) |
| Zdroj: | Journal of Power Sources. 267:269-279 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2014.05.070 |
| Popis: | In this work composite (1–x)Ce 0.8 Nd 0.2 O 2– δ –xBaCe 0.8 Nd 0.2 O 3– δ ceramics were prepared via the one-step citrate-nitrate combustion procedure, and characterised by TG-DSC, XRD analysis, and SEM. Their transport properties were investigated across various temperatures (600–900 ° C) and oxygen partial pressures (10 −23 –0.21 atm). The XRD data reveals an occurrence of single-phase oxides at x = 0, 1 and two phases with perovskite and fluorite structure at x = 0.25, 0.5, 0.75 in powders calcined at 1100 ° C. Dense ceramic samples (93–95%) were sintered in air at 1500 °C for 3 h. The concentration dependence of the mean grain size is characterized by local minimum at x = 0.5, while that of total conductivity exhibited a similar behavior; its minimal value was registered in the sample with the most extended specific grain surface. It was found that the electronic contribution to the total conductivity of the composites is reduced as compared to that of the basic Ce 0.8 Nd 0.2 O 2– δ and BaCe 0.8 Nd 0.2 O 3– δ materials. This leads to a better stability in the long-term redox-cycles in comparison with the basic oxides. Additionally, the conductivity in Ce 0.8 Nd 0.2 O 2– δ decreases by 85%, whereas the conductivity of BaCe 0.8 Nd 0.2 O 3– δ decreases by 30% after 2 redox-cycles for 200 h at 900 °C. The resulting conductivity degradation of the (1–x)Ce 0.8 Nd 0.2 O 2– δ –xBaCe 0.8 Nd 0.2 O 3– δ composite is no more than 15%. |
| Databáze: | OpenAIRE |
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