2013 Fiscal Year Final Research Report
Computational research of ionic conductance mechanism in bulk and interfaces of proton conductive oxides
| Project/Area Number |
23760629
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Physical properties of metals
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| Research Institution | Japan Fine Ceramics Center |
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Principal Investigator |
KUWABARA Akihide 一般財団法人ファインセラミックスセンター, その他部局等, 研究員 (30378799)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 固体酸化物燃料電池 / プロトン伝導体 / 第一原理計算 / 点欠陥 / 拡散 |
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| Research Abstract |
Theoretical calculations based on density functional theory have been systematically performed to compute the point defect formation behavior of BaZrO3. Thermal equilibrium defect concentrations are evaluated including defect association models. Our calculations have quantitatively revealed that stoichiometry strongly affects defect formation behavior in BaZrO3. Ba-rich condition is necessary for synthesizing proton conductive BaZrO3. If phase equilibrium condition of BaZrO3 samples changes to opposite Zr-rich side, hydration reaction is suppressed by dopants substituted for Ba sites. Hydration of oxide vacancy by water molecules associated with temperature decreasing is successfully reproduced by calculations based on DFT and thermodynamics. Calculations of association energy show that protons are mostly bound with trivalent acceptor dopants at lower temperature conditions. In order to improve proton conductivity in oxides, dopants showing low association energy need to be chosen.
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