| Project/Area Number |
23760638
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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 |
Inorganic materials/Physical properties
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Project Period (FY) |
2011 – 2012
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| Project Status |
Completed (Fiscal Year 2012)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2012: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2011: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | イオン伝導 / 第一原理計算 / プロトン / リン酸塩 / プロトン伝導 / ランタンリン酸塩 |
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| Research Abstract |
In the present study, the proton conduction mechanisms in lanthanum phosphates have been theoretically evaluated at the atomic levels using first -principles calculations, to obtain a guideline for materials design of proton-conducting oxides. Specifically, the proton sites, migration paths, potential barriers, and dopant-association effects have been investigated in the lanthanum orthophosphate (LaPO_4) and polyphosphate (LaP_3O_9). As the results, the calculated proton conductivity of LaPO_4 is almost isotropic with a potential barrier of 0.7 eV. On the other hand, LaP_3O_9 has large anisotropic proton conductivity, whose potential barriers are 0.34 eV in bc-plane vs. 1.0 eV along a-axis. In addition, the Sr-H association makes the apparent activation energies of proton conductivities steeper by 0.1-0.2 eV in LaPO_4 and 0.5-0.6 eV in LaP_3O_9.The above results indicate the proton conductivity of lanthanum polyphosphate (LaP_3O_9) can bedrastically improved by controlling the crystal orientation and selecting more appropriate dopants.
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