2013 Fiscal Year Final Research Report
Atomistic modeling toward the understanding of defect kinetics and degradation mechanism in solid systems
| Project/Area Number |
23760087
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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 |
Materials/Mechanics of materials
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HARA Shotaro 東京大学, 生産技術研究所, 特任講師 (10401134)
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| Project Period (FY) |
2011 – 2012
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| Keywords | 計算物理 / ナノ材料 / 材料強度 / 分子動力学 / 拡散 / 固体酸化物形燃料電池 |
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| Research Abstract |
Long-term degradation processes in solid oxide fuel cell (SOFC) are mainly governed by the cation diffusion. However, the cation diffusion is a considerably slow process compared with the oxygen diffusion, such that a molecular dynamics is not generally suitable to predict the rate for the cation migration due to its limited time scale. In this work, we have investigated a vacancy-mediated cation diffusion in YSZ by utilizing metadynamics and Kinetic Monte Carlo method. Metadynamics simulations allow us to compute temperature-dependent activation free energy of cation migration in the typical experimental temperature range of SOFC. Beside, our Kinetic Monte Carlo simulations successfully provide a diffusion coefficient for Zr and Y in 8 mol% YSZ, which is in good agreement with an experimental result.
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