Development of new surface electron diffraction method and evaluation of electron density distribution

• Project/Area Number: 18H01877
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Fukaya Yuki 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 先端基礎研究センター, 研究主幹 (40370465)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥18,070,000 (Direct Cost: ¥13,900,000、Indirect Cost: ¥4,170,000); Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2018: ¥14,690,000 (Direct Cost: ¥11,300,000、Indirect Cost: ¥3,390,000)
• Keywords: 電子回折 / 表面 / 電子密度分布

Outline of Final Research Achievements

In this study, we developed convergent-beam reflection high-energy electron diffraction to obtain the information on atomic coordinates and electron density distributions at material surfaces. The electron gun consists of two condenser lens and enables to vary the convergence angle of the election beam at sample and screen positions. We measured diffraction discs for a Si(111)-7x7 surface and confirmed the intensity distribution originated from the surface structure. By further improvement of the intensity analysis, we are able to determine the electron density distributions at material surfaces, together with the atomic configurations.

Academic Significance and Societal Importance of the Research Achievements

物質表面は原子分子と反応する最前線であり、ナノ構造を創製する重要な舞台でもある。物質表面やナノ構造の特性を理解するには、その原子配置と電子密度分布の双方の情報が欠かせない。これまで、表面ナノ構造の複雑な原子配置を決定する手法は確立しているものの、それと同時に電子密度分布まで決定するには至っていない。本研究の成果は、表面ナノ構造の特異な構造物性の理解を促進するとともに、それを基にした新たな物質設計にもつながる。

Research Products

• [Journal Article] Emergence of nearly flat bands through a kagome lattice embedded in an epitaxial two-dimensional Ge layer with a bitriangular structure (2020)
  • Author(s): A. Fleurence, C.-C. Lee, R. Friedlein, Y. Fukaya, S. Yoshimoto, K. Mukai, H. Yamane, N. Kosugi, J. Yoshinobu, T. Ozaki, and Y. Yamada-Takamura
  • Journal Title: Physical Review B Volume: 102 Issue: 20
  • DOI: 10.1103/physrevb.102.201102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Electronic structure of a (3×3)-ordered silicon layer on Al(111) (2020)
  • Author(s): Sato Yusuke、Fukaya Yuki、Cameau Mathis、Kundu Asish K.、Shiga Daisuke、Yukawa Ryu、Horiba Koji、Chen Chin-Hsuan、Huang Angus、Jeng Horng-Tay、Ozaki Taisuke、Kumigashira Hiroshi、Niibe Masahito、Matsuda Iwao
  • Journal Title: Physical Review Materials Volume: 4 Issue: 6 Pages: 0640051-6
  • DOI: 10.1103/physrevmaterials.4.064005
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Structure of superconducting Ca-intercalated bilayer Graphene/SiC studied using total-reflection high-energy positron diffraction (2020)
  • Author(s): Endo Y.、Fukaya Y.、Mochizuki I.、Takayama A.、Hyodo T.、Hasegawa S.
  • Journal Title: Carbon Volume: 157 Pages: 857-862
  • DOI: 10.1016/j.carbon.2019.10.070
  • Peer Reviewed
• [Journal Article] 全反射高速陽電子回折法（TRHEPD） (2019)
  • Author(s): 深谷有喜
  • Journal Title: 陽電子科学 Volume: 13 Pages: 3-10
  • NAID: 40022010003
  • Peer Reviewed
• [Presentation] 回折 (2020)
  • Author(s): 深谷有喜
  • Organizer: 日本表面真空学会 東北・北海道支部 関東支部合同セミナー「特別企画：これまでの表面薄膜分析シリーズを振り返って」
  • Invited
• [Presentation] Al(111)基板上のシリコン原子層の電子構造 (2020)
  • Author(s): 佐藤祐輔，深谷有喜，M. Cameau，A.K. Kundu，志賀大亮，湯川龍，堀場弘司，C.H. Chen，A. Huang，H.T. Jeng，M. D'angelo，組頭広志，新部正人，松田巌
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] Growth mechanism of twisted graphene layers on graphene/silicon carbide template (2020)
  • Author(s): Y. Yao, R. Negishi, D. Takajo, Y. Fukaya, M. Takamura, Y. Taniyasu, Y. Kobayashi
  • Organizer: 第67回応用物理学会春季学術講演会
• [Presentation] Al(111)基板上のシリセンの電子構造の研究 (2019)
  • Author(s): 佐藤祐輔，深谷有喜，M. Cameau，A.K. Kundu, C.H. Chen，A. Huang，H.T. Jeng，M. D'angelo，新部正人，松田巌
  • Organizer: 2019年日本表面真空学会学術講演会
• [Presentation] Al(111)基板上のシリセンの電子構造の研究 (2019)
  • Author(s): 佐藤祐輔，深谷有喜，M. Cameau，C.H. Chen，A. Huang，H.T. Jeng，M. D'angelo，新部正人，松田巌
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Present Status of the Slow Positron Facility of Institute of Materials Structure Science, KEK (2019)
  • Author(s): I. Mochizuki, K. Wada, Y. Fukaya, T. Shirasawa, Y. Endo, A. Takayama, S. Hasegawa, A. Ichimiya, Y. Nagashima, M. Maekawa, A. Kawasuso, A. Ishida, N. Toge, K. Furukawa, Y. Nagai, T. Hyodo
  • Organizer: 15th International Workshop on Slow Positron Beam Techniques & Applications (SLOPOS-15)
  • Int'l Joint Research
• [Presentation] Recent Studies of Surface Structure Analysis with Total-Reflection High-Energy Positron Diffraction (TRHEPD) at Slow-Positron Facility, KEK (2019)
  • Author(s): I. Mochizuki, Y. Fukaya, Y. Endo, A. Takayama, S. Hasegawa, A. Ichimiya, T. Hyodo
  • Organizer: 15th International Workshop on Slow Positron Beam Techniques & Applications (SLOPOS-15)
  • Int'l Joint Research / Invited
• [Book] ポストグラフェン材料の創製と用途開発最前線 (2020)
  • Author(s): 深谷有喜（分担執筆）
  • Total Pages: 448
  • Publisher: エヌ・ティー・エス
• [Book] 2020版 薄膜作製応用ハンドブック (2020)
  • Author(s): 深谷有喜（分担執筆）
  • Total Pages: 1570
  • Publisher: エヌ・ティー・エス
• [Book] Monatomic Two-Dimensional Layers: Modern Experimental Approaches for Structure, Properties, and Industrial Use (Micro and Nano Technologies) (2018)
  • Author(s): Y. Fukaya（分担執筆）
  • Total Pages: 232
  • Publisher: Elsevier
  • ISBN: 9780128141601