ID | 48849 |
フルテキストURL | |
著者 |
Noami, K.
Graduate School of Natural Science and Technology, Okayama University
Muraoka, Y.
Graduate School of Natural Science and Technology, Okayama University
Kaken ID
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Wakita, T.
Faculty of Science, Research Laboratory for Surface Science, Okayama University
Hirai, M.
Graduate School of Natural Science and Technology, Okayama University
Kato, Y.
Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8
Muro, T.
Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8
Tamenori, Y.
Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8
Yokoya, T.
Graduate School of Natural Science and Technology, Okayama University
ORCID
Kaken ID
publons
researchmap
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抄録 | A hollandite-type K(x)Ti(8)O(16) polycrystalline sample has been prepared and studied by magnetization, resistivity and x-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behavior is observed in the magnetic hysteresis measurement. The sample shows a semiconductive temperature dependence in the resistivity measurement. Analysis of the Ti 2p(3/2) core-level XPS spectrum indicates that the titanium ions have a mixed valence of Ti(4+) and Ti(3+). In addition, the valence band spectrum reveals that the 3d electrons tend to localize on Ti(3+) ions in the hollandite-type TiO(2) lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type K(x)Ti(8)O(16) sample can be classified as a TiO(2)-based wide-gap semiconductor with Curie temperature above room temperature. Room temperature ferromagnetism (RTFM) decreases in the sample prepared under a strong reducing gas atmosphere, accompanied with the decrease in the resistivity. The results imply that the localized 3d electrons are responsible for the RTFM of the K(x)Ti(8)O(16) sample.
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発行日 | 2010-04-01
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出版物タイトル |
Journal of Applied Physics
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巻 | 107巻
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号 | 7号
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出版者 | American Institute of Physics.
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開始ページ | 073910-1
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終了ページ | 073910-6
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ISSN | 0021-8979
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資料タイプ |
学術雑誌論文
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プロジェクト |
エネルギー環境新素材拠点
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オフィシャル URL | http://dx.doi.org/10.1063/1.3369500
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言語 |
英語
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著作権者 | © 2010 American Institute of Physics.
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論文のバージョン | publisher
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査読 |
有り
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DOI | |
Web of Science KeyUT |