| Project/Area Number |
16K05458
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Sophia University |
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Principal Investigator |
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| Research Collaborator |
SUMURA takuya
KAWABATA koki
PARK sangeun
BAQIYA malik anjelh
KURASHIMA koshi
ONISHI shusei
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | 高温超伝導体 / 電子ドープ型銅酸化物 / 母物質ノンドープ超伝導 / 還元処理 / ミュオンスピン緩和 / Ｘ線吸収分光 / 単結晶 / マイスナー反磁性 / 光学反射率 / 単結晶育成 / 強相関電子系 / 超伝導材料・素子 / 低温物性 / 粒子線 / 磁性 |
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| Outline of Final Research Achievements |
In order to elucidate the mechanism of superconductivity in the parent compounds of the electron-doped high-Tc cuprate superconductors with the T'-structure, we have investigated detailed changes of the electronic states through the reduction annealing from the electrical resistivity, muon spin relaxation etc. using single crystals of the T'-cuprates.
By improving the reduction annealing, we have succeeded in removing effectively the excess oxygen from the single crystals of the T'-cuprates. It has been clarified that not only electrons but also holes are generated through the reduction annealing in the T'-cuprates, suggesting that holes are related to the appearance of superconductivity. Moreover, it has been clarified that the Cu-spin correlation and superconductivity are in intimate relation with each other in the T'-cuprates.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究の結果、電子ドープ型T'銅酸化物から過剰な酸素を効果的に取り除く方法を確立した。これは、他の遷移金属酸化物に対しても利用できる技術なので、様々な機能性酸化物の開発に貢献するだろう。
本研究から、T'銅酸化物において還元とともに電子状態がどのように変化するのかが明らかになった。特に、超伝導が発現する試料におけるホールキャリアの存在とCuスピン相関の発達を結論できたことは特筆に値する。今後は、元素置換によらない新たなキャリアドープ法による新規高温超伝導体の創製が発展するだろう。
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