Control of surface electronic states for anatase TiO2 thin film by interface engineering

• Project/Area Number: 15K17470
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Minohara Makoto 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 特別助教 (70728633)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2015: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 酸化物表面・界面 / 酸化物界面

Outline of Final Research Achievements

We have investigated the electronic structure of polar/nonpolar oxide heterointerfaces between (001)-oriented LaFeO3 film and Nb:SrTiO3 substrate with different interfacial termination layer using x-ray photoemission spectroscopy. A certain built-in potential forms in Nb:SrTiO3 substrate for the LaFeO3/SrO-Nb:SrTiO3, while almost flat band is maintained even after the LaFeO3 deposition for the LaFeO3/TiO2-Nb:SrTiO3. Since the estimated charge in the depletion layer is not sufficient to solve the polarity mismatch, the electronic reconstruction are presumably occurred in both sides of the LaFeO3 film and the Nb:SrTiO3 substrate. Moreover, the valence band spectra of thick LaFeO3 films rigidly shifts ~0.4 eV by changing the interfacial termination layer. This result indicates the different internal potential formation in LaFeO3 film depending on the interfacial polarity, supporting the abovementioned interpretation on the possible electric reconstruction in LaFeO3 layer.

Research Products

• [Journal Article] Thickness dependence and dimensionality effects on charge and magnetic orderings in La1/3Sr2/3FeO3 thin films (2018)
  • Author(s): K. Yamamoto, Y. Hirata, M. Horio, Y. Yokoyama, K. Takubo, M. Minohara, H. Kumigashira, Y. Yamasaki, H. Nakao, Y. Murakami, A. Fujimori, and H. Wadati
  • Journal Title: Phys. Rev. B Volume: 97 Issue: 7 Pages: 75134-75134
  • DOI: 10.1103/physrevb.97.075134
  • Peer Reviewed
• [Journal Article] Atomically-engineered epitaxial anatase TiO2 metal-semiconductor field-effect transistors (2018)
  • Author(s): B. S. Y. Kim, M. Minohara, Y. Hikita, C. Bell, and H. Y. Hwang
  • Journal Title: Appl. Phys. Lett. Volume: 112 Issue: 13 Pages: 133506-133506
  • DOI: 10.1063/1.5024418
  • Peer Reviewed
• [Journal Article] Dielectric collapse at the LaAlO3/SrTiO3 (001) heterointerface under applied electric field (2017)
  • Author(s): M. Minohara, Y. Hikita, C. Bell, H. Inoue, M. Hosoda, H. K. Sato, H. Kumigashira, M. Oshima, E. Ikenaga, and H. Y. Hwang
  • Journal Title: Scientific Report Volume: VOL. 7 Issue: 1 Pages: 9516-9516
  • DOI: 10.1038/s41598-017-09920-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Thickness-dependent physical properties of La1/3Sr2/3FeO3 thin films grown on SrTiO3 (001) and (111) substrates (2016)
  • Author(s): Makoto Minohara, Miho Kitamura, Hiroki Wadati, Hironori Nakao, Reiji Kumai, Youichi Murakami, and Hiroshi Kumigashira
  • Journal Title: Journal of Applied Physics Volume: 120 Issue: 2 Pages: 025303-025303
  • DOI: 10.1063/1.4958670
  • Peer Reviewed
• [Journal Article] Influence of k⊥-broadening on ARPES spectra of the (110) and (001) surfaces of SrVO3 films (2016)
  • Author(s): T. Mitsuhashi, M. Minohara, R. Yukawa, M. Kitamura, K. Horiba, M. Kobayashi, and H. Kumigashira
  • Journal Title: Phys. Rev. B Volume: 94 Issue: 12 Pages: 125148-125148
  • DOI: 10.1103/physrevb.94.125148
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] PLD法によるアンチペロブスカイト型酸化物 Ca3SnO薄膜の作製 (2017)
  • Author(s): 簔原 誠人、湯川 龍、組頭 広志
  • Organizer: 第64回 応用物理学会春季学術講演会
  • Place of Presentation: パシフィコ横浜（神奈川県・横浜市）
• [Presentation] 面方位制御La1/3Sr2/3FeO3薄膜における 電荷不均化の膜厚依存性 (2017)
  • Author(s): 簔原誠人、北村未歩、和達大樹、中尾裕則、熊井玲児、村上洋一、組頭広志
  • Organizer: 第30回 日本放射光学会年会・放射光科学合同シンポジウム
  • Place of Presentation: 神戸技術センター（兵庫県・神戸市）
• [Presentation] 面方位制御La1/3Sr2/3FeO3薄膜における電荷不均化の膜厚依存性 (2016)
  • Author(s): 簑原誠人、北村未歩、和達大樹、組頭広志
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学大岡山キャンパス（東京、目黒区）
  • Year and Date: 2016-03-20
• [Presentation] 終端面制御したLaFeO3/Nb:SrTiO3ヘテロ接合界面の電子状態 (2016)
  • Author(s): 簑原誠人、北村未歩、三橋太一、小林正起、堀場弘司、組頭広志
  • Organizer: 第29回日本放射光学会年会・放射光科学合同シンポジウム
  • Place of Presentation: 柏の葉カンファレンスセンター（千葉、柏市）
  • Year and Date: 2016-01-10
• [Presentation] Thickness Dependent Physical Properties of La1/3Sr2/3FeO3 Thin Films Grown on SrTiO3 (001) and (111) Substrates (2016)
  • Author(s): M. Minohara, M. Kitamura, H. Wadati, H. Nakao, R, Kumai, Y. Murakami, and H. Kumigashira
  • Organizer: International Workshop on Oxide Electronics 23
  • Place of Presentation: 南京（中国）
  • Int'l Joint Research
• [Presentation] 終端面制御したLaFeO3/Nb:SrTiO3ヘテロ接合界面の電子状態 (2015)
  • Author(s): 簑原誠人、北村未歩、三橋太一、小林正起、堀場弘司、組頭広志
  • Organizer: 第60回応用物理学会春季学術講演会
  • Place of Presentation: 名古屋国際会議場（愛知、名古屋市）
  • Year and Date: 2015-09-14