電気二重層トランジスタ動作下の軟X線吸収分光計測

2022 Fiscal Year Annual Research Report

• Project/Area Number: 20K20906
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: 堀場 弘司 国立研究開発法人量子科学技術研究開発機構, 関西光量子科学研究所 放射光科学研究センター, 上席研究員 (10415292)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: オペランド軟X線吸収分光 / 転換可視蛍光収量 / 電気二重層トランジスタ

Outline of Annual Research Achievements

近年、強相関酸化物に対するキャリアドープによる物性変調・巨大応答発現の手法として、電気二重層トランジスタ（EDLT）構造によるキャリア蓄積が大きな成功を収めているが、この動作メカニズムとして酸化物への酸素欠損誘起、水素イオンの注入、物質自体のエッチング効果など、純粋なキャリアドープ以外の様々な効果が報告され、議論が収束していない物質例も多い。このようなEDLTの複雑な動作メカニズムを解明していくためには、その輸送特性の測定のみでは不十分であり、結晶構造解析や分光測定による電子状態解析など様々な測定手法を組み合わせることが必要不可欠である。軟X線吸収分光（XAS）は、特に軽元素の元素選択的な電子状態を直接観測できる優れた手法であるが、これまでEDLT動作時のキャリア蓄積領域のXAS観測の成功例は報告されていない。その理由は、使用する軟X線の物質への侵入長が非常に短いため、イオン液体を透過させることが困難であるという本質的な問題に起因する。そこで本申請では、転換可視蛍光収量という新たなXAS測定手法によりイオン液体透過時の減衰を低減させ、EDLT動作時のキャリア蓄積領域のXAS観測を達成することを目的としている。
これまで開発を進めてきた転換可視蛍光収量軟X線吸収分光測定装置およびデバイス動作中のオペランドXAS観測を可能とするための試料ステージを用いて、Liイオン電池における電圧印加中XAS観測を行い、オペランドXAS観測に成功した。令和4年度の研究実績としては、EDLTに必要となるイオン液体の薄膜化に取り組み、実際にイオン液体を塗布した遷移金属酸化物基板においてイオン液体を透過した軟X線による下部酸化物の軟X線吸収スペクトルが取得可能であることを実証した。

Research Products

• [Journal Article] Direct Imaging of Band Structure for Powdered Rhombohedral Boron Monosulfide by Microfocused ARPES (2023)
  • Author(s): K. Sugawara, H. Kusaka, T. Kawakami, K. Yanagizawa, A. Honma, S. Souma, K. Nakayama, M. Miyakawa, T. Taniguchi, M. Kitamura, K. Horiba, H. Kumigashira, T. Takahashi, S. Orimo, M. Toyoda, S. Saito, T. Kondo, and T. Sato
  • Journal Title: Nano Letters Volume: 23 Pages: 1673~1679
  • DOI: 10.1021/acs.nanolett.2c04048
  • Peer Reviewed
• [Journal Article] Redox Reaction in Ti-Mn Redox Flow Battery Studied by X-ray Absorption Spectroscopy (2023)
  • Author(s): D. Asakura, E. Hosono, M. Kitamura, K. Horiba, E. Magome, H. Setoyama, E. Kobayashi, H. Yuzawa, T. Ohigashi, T. Sakai, R. Kanega, T. Funaki, Y. Sato, and A. Ohira
  • Journal Title: Chemistry-An Asian Journal Volume: 18 Pages: e202201047-1~9
  • DOI: 10.1002/asia.202201047
  • Peer Reviewed
• [Journal Article] Design of nano-ARPES beamline at 3-GeV next-generation synchrotron radiation facility, NanoTerasu (2022)
  • Author(s): K. Horiba, T. Imazono, H. Iwasawa, K. Fujii, J. Miyawaki, Y. Ohtsubo, N. Inami, T. Nakatani, K. Inaba, A. Agui, H. Kimura, and M. Takahasi
  • Journal Title: Journal of Physics: Conference Series Volume: 2380 Pages: 012034-1~6
  • DOI: 10.1088/1742-6596/2380/1/012034
  • Peer Reviewed
• [Journal Article] Fermiology and Origin of Tc Enhancement in a Kagome Superconductor Cs(V1-xNbx)3Sb5 (2022)
  • Author(s): T. Kato, Y. Li, K. Nakayama, Z. Wang, S. Souma, F. Matsui, M. Kitamura, K. Horiba, H. Kumigashira, T. Takahashi, Y. Yao, and T. Sato
  • Journal Title: Physical Review Letters Volume: 129 Pages: 047002-1~7
  • DOI: 10.1103/PhysRevLett.129.206402
  • Peer Reviewed
• [Journal Article] Low-temperature-processable amorphous-oxide- semiconductor-based phosphors for durable light-emitting diodes (2022)
  • Author(s): K. Ide, N. Watanabe, T. Katase, M. Sasase, J. Kim, S. Ueda, K. Horiba, H. Kumigashira, H. Hiramatsu, H. Hosono, and T. Kamiya
  • Journal Title: Applied Physics Letters Volume: 121 Pages: 192108-1~6
  • DOI: 10.1063/5.0115384
  • Peer Reviewed
• [Journal Article] Signature of topological band crossing in ferromagnetic Cr1/3NbSe2 epitaxial thin film (2022)
  • Author(s): B. K. Saika, S. Hamao, Y. Majima, X. Huang, H. Matsuoka, S. Yoshida, M. Kitamura, M. Sakano, T. Hatanaka, T. Nomoto, M. Hirayama, K. Horiba, H. Kumigashira, R. Arita, Y. Iwasa, M. Nakano, and K. Ishizaka
  • Journal Title: Physical Review Research Volume: 4 Pages: L042021-1~7
  • DOI: 10.1103/PhysRevResearch.4.L042021
  • Peer Reviewed / Open Access
• [Journal Article] Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: Angle-resolved photoemission study (2022)
  • Author(s): C.-W. Chuang, S. Souma, A. Moriya, K. Nakayama, A. Ikeda , M. Kawaguchi, K. Obata, S. Saha, H. Takahashi, S. Kitagawa, K. Ishida, K. Tanaka, M. Kitamura, K. Horiba, H. Kumigashira, T. Takahashi, S. Yonezawa, J. Paglione, Y. Maeno, and T. Sato
  • Journal Title: Physical Review Materials Volume: 6 Pages: 104203-1~6
  • DOI: 10.1103/PhysRevMaterials.6.104203
  • Peer Reviewed
• [Journal Article] Metallic Surface State in the Bulk Insulating Phase of Ca2-xSrxRuO4 (x = 0.06) Studied by Photoemission Spectroscopy (2022)
  • Author(s): D. Ootsuki, A. Hishikawa, T. Ishida, D. Shibata, Y. Takasuka, M. Kitamura, K. Horiba, Y. Takagi, A. Yasui, C. Sow, S. Yonezawa, Y. Maeno, and T. Yoshida
  • Journal Title: Journal of the Physical Society of Japan Volume: 91 Pages: 114704-1~6
  • DOI: 10.7566/JPSJ.91.114704
  • Peer Reviewed
• [Journal Article] Giant spin-to-charge conversion at an all-epitaxial single-crystal-oxide Rashba interface with a strongly correlated metal interlayer (2022)
  • Author(s): S. Kaneta-Takada, M. Kitamura, S. Arai, T. Arai, R. Okano, L. Anh, T. Endo, K. Horiba, H. Kumigashira, M. Kobayashi, M. Seki, H. Tabata, M. Tanaka, and S. Ohya
  • Journal Title: Nature Communications Volume: 13 Pages: 5631-1~8
  • DOI: 10.1038/s41467-022-33350-5
  • Peer Reviewed / Open Access
• [Journal Article] Polarity-dependent charge density wave in the kagome superconductor CsV3Sb5 (2022)
  • Author(s): T. Kato, Y. Li, K. Nakayama, Z. Wang, S. Souma, M. Kitamura, K. Horiba, H. Kumigashira, T. Takahashi, and T. Sato
  • Journal Title: Physical Review B Volume: 106 Pages: L121112-1~7
  • DOI: 10.1103/PhysRevB.106.L121112
  • Peer Reviewed
• [Journal Article] Anomalously large spin-dependent electron correlation in the nearly half-metallic ferromagnet CoS2 (2022)
  • Author(s): H. Fujiwara, K. Terashima, J. Otsuki, N. Takemori, H. O. Jeschke, T. Wakita, Y. Yano, W. Hosoda, N. Kataoka, A. Teruya, M. Kakihana, M. Hedo, T. Nakama, Y. Onuki, K. Yaji, A. Harasawa, K. Kuroda, S. Shin, K. Horiba, H. Kumigashira, Y. Muraoka, and T. Yokoya
  • Journal Title: Physical Review B Volume: 106 Pages: 085114-1~13
  • DOI: 10.1103/PhysRevB.106.085114
  • Peer Reviewed
• [Journal Article] Rhombic Fermi surfaces in a ferromagnetic MnGa thin film with perpendicular magnetic anisotropy (2022)
  • Author(s): M. Kobayashi, N. H. D. Khang, T. Takeda, K. Araki, R. Okano, M. Suzuki, K. Kuroda, K. Yaji, K. Sugawara, S. Souma, K. Nakayama, K. Yamauchi, M. Kitamura, K. Horiba, A. Fujimori, T. Sato, S. Shin, M. Tanaka, and P. N. Hai
  • Journal Title: Phys. Rev. Materials Volume: 6 Pages: 074403-1~7
  • DOI: 10.1103/PhysRevMaterials.6.074403
  • Peer Reviewed
• [Journal Article] Electronic band structure of Ti2O3 thin films studied by angle-resolved photoemission spectroscopy (2022)
  • Author(s): N. Hasegawa, K. Yoshimatsu, D. Shiga, T. Kanda, S. Miyazaki, M. Kitamura, K. Horiba, and H. Kumigashira
  • Journal Title: Physical Review B Volume: 105 Pages: 235137-1~8
  • DOI: 10.1103/PhysRevB.105.235137
  • Peer Reviewed
• [Journal Article] Intervalence charge transfer and charge transport in the spinel ferrite ferromagnetic semiconductor Ru-doped CoFe2O4 (2022)
  • Author(s): M. Kobayashi, M. Seki, M. Suzuki, R. Okano, M. Kitamura, K. Horiba, H. Kumigashira, A. Fujimori, M. Tanaka, and H. Tabata
  • Journal Title: Physical Review B Volume: 105 Pages: 205103-1~6
  • DOI: 10.1103/PhysRevB.105.205103
  • Peer Reviewed
• [Journal Article] Development of magnetism in Fe-doped magnetic semiconductors: Resonant photoemission and x-ray magnetic circular dichroism studies of (Ga,Fe)As (2022)
  • Author(s): T. Takeda, S. Sakamoto, L. Anh, Y. Takeda, S. Fujimori, M. Kitamura, K. Horiba, H. Kumigashira, A. Fujimori, M. Tanaka, and M. Kobayashi
  • Journal Title: Physical Review B Volume: 105 Pages: 195155-1~10
  • DOI: 10.1103/PhysRevB.105.195155
  • Peer Reviewed
• [Journal Article] Development of a versatile micro-focused angle-resolved photoemission spectroscopy system with Kirkpatrick-Baez mirror optics (2022)
  • Author(s): M. Kitamura, S. Souma, A. Honma, D. Wakabayashi, H. Tanaka, A. Toyoshima, K. Amemiya, T. Kawakami, K. Sugawara, K. Nakayama, K. Yoshimatsu, H. Kumigashira, T. Sato, and K. Horiba
  • Journal Title: Review of Scientific Instruments Volume: 93 Pages: 033906-1~8
  • DOI: 10.1063/5.0074393
  • Peer Reviewed
• [Journal Article] Crystal structure and electronic property modification of Ca2RuO4 thin films via fluorine doping (2022)
  • Author(s): S. Fukuma, A. Chikamatsu, T. Katayama, T. Maruyama, K. Yanagisawa, K. Kimoto, M. Kitamura, K. Horiba, H. Kumigashira, Y. Hirose, and T. Hasegawa
  • Journal Title: Phys. Rev. Materials Volume: 6 Pages: 035002-1~5
  • DOI: 10.1103/PhysRevMaterials.6.035002
  • Peer Reviewed