2016 Fiscal Year Final Research Report
Fast diffusion mechanism of hydroxide ions in oxides
| Project/Area Number |
15K14123
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Kyoto University (2016)
Nagoya University (2015) |
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Principal Investigator |
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| Project Period (FY) |
2015-04-01 – 2017-03-31
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| Keywords | 水酸化物イオン伝導 / プロトン伝導 / ピロリン酸塩 / 第一原理分子動力学法 / nudged elastic band法 / kinetic Monte Carlo法 |
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| Outline of Final Research Achievements |
The incorporation and conduction mechanisms of hydroxide ions in tin pyrophosphate (SnP2O7) have been investigated theoretically on the basis of first-principles calculations. Hydroxide ions are not simply incorporated into interstitial sites in the crystal, and the incorporation is accompanied by dissociation of a P2O7 unit (pyrophosphate ion) into two PO4 units. The long-range migration of the hydroxide ion was observed in the first-principles molecular dynamics simulations, but its frequency during the simulation was extremely low. In fact, the calculated potential barrier for the conduction pathway was extremely high (1.92 eV), and the estimated bulk conductivity in SnP2O7 was much lower than the experimentally reported conductivities. These results indicate that the experimentally observed hydroxide-ion conductivity of SnP2O7 cannot be simply explained by motion of hydroxide ions through the crystal lattice.
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| Free Research Field |
計算材料科学
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