2018 Fiscal Year Final Research Report
Soft chemical doping to a graphite structure magnesium alloy and its superconducting properties
| Project/Area Number |
17K18986
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Materials engineering and related fields
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Research Collaborator |
MORI Takahiro
KINTSU Kohei
TAKEOKA Shun
TSUCHIDA Naoki
ZHANG Zelei
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| Project Period (FY) |
2017-06-30 – 2019-03-31
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| Keywords | 超伝導 / 二ホウ化マグネシウム / 薄膜試料 / 臨海電流密度Jc / 非水系電解液 / ドーピング |
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| Outline of Final Research Achievements |
Soft-chemical doping was performed to a graphite-structured magnesium alloy superconductor, magnesium diboride (MgB2) thin film. It was clarified that its critical current density (Jc) improved by doping. Decrease of critical temperature (Tc) was not observed, suggesting that the increase of Jc was caused by introduction of pinning center.
Whether doping can be done was examined for powder sample and c-axis oriented thin film sample. As for powder samples, we found it difficult to perform the aimed reaction due to large resistivity at the interface because there are thick surface oxide films. As we used thin film samples on which the oxide film formation was suppressed, oxidation currents possibly due to desertion of magnesium ions were observed. In addition, improvement of Jc was observed, especially at high magnetic fields.
Other findings through the survey of soft-chemical doping methods are novel ethereal nonaqueous electrolytes.
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| Free Research Field |
無機材料科学
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| Academic Significance and Societal Importance of the Research Achievements |
MgB2は熱力学的にきわめて安定な組成であり、高温固相反応によるドーピングは困難である。これに対して、速度論に立脚した室温付近でのソフト化学的ドーピングを行った。超伝導特性を向上させる上での新しいアプローチを提案した。加えて、新規電解液材料も数多く見出した。
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