Takehito Seki




Assistant Professor, Institute of Engineering Innovation, School of Engineering
PRESTO Researcher, Japan Science and Technology Agency

  Yayoi 2-11-16, Bunkyo-ku, Tokyo, Japan, 113-8656
  Phone +81-3-5841-7689
  Fax +81-3-5841-7694
  mail: seki     sigma.t.u-tokyo.ac.jp(please insert @ instead of space)



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  • Electron Microscopy & Materials Science Laboratory
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    • Contents

  • Profile
  • Research
  • Publication list
  • Invited Talks
  • Awards


    • Profile



  • 2021 - 　　　　 JST PRESTO (Concurrent position).
  • 2019 - 　　　　 Assistant Professor, The University of Tokyo.
  • 2015 - 2019 Poctdoctoral Fellow, The University of Tokyo.
  • 2014 - 2015 JSPS Research Fellowship (PD)
  • 2013 - 2014 JSPS Research Fellowship (DC2)
  • 2011 - 2014 Ph.D. The University of Tokyo




    • Research



    STEM Imaging Using a Segmented Detector

    Complex metallic alloy





    Publication list



    Peer Review Papers

    1. S. Toyama, T. Seki, Y. Kanitani, Y. Kudo, S. Tomiya, Y. Ikuhara, N. Shibata, "Real-space observation of a two-dimensional electron gas at semiconductor heterointerfaces",
      Nature Nanotechnology .

    2. T. Seki, K. Khare, Y. O. Murakami, S. Toyama, G. Sánchez-Santolino, H. Sasaki, S. D. Findlay, T. C. Petersen, Y. Ikuhara, N. Shibata, "Linear imaging theory for differential phase contrast and other phase imaging modes in scanning transmission electron microscopy",
      Ultramicroscopy 240 (2022) 113580.

    3. S. Toyama, T. Seki, Y. Kanitani, Y. Kudo, S. Tomiya, Y. Ikuhara, N. Shibata, "Quantitative electric field mapping in semiconductor heterostructures via tilt-scan averaged DPC STEM",
      Ultramicroscopy 238 (2022) 113538.

    4. T. Mawson, D. Taplin, H. Brown, L. Clark, R. Ishikawa, T. Seki, Y. Ikuhara, N. Shibata, D. Paganin, M. Morgan, M. Weyland, T. Petersen, S. Findlay, "Factors limiting quantitative phase retrieval in atomic-resolution differential phase contrast scanning transmission electron microscopy using a segmented detector",
      Ultramicroscopy 233 (2022) 113457.

    5. Y. Kohno, T. Seki, S. D. Findlay, Y. Ikuhara, N. Shibata, "Real-space visualization of intrinsic magnetic fields of an antiferromagnet",
      Nature 602 (2022) 234-239.

    6. R. Tamura, A. Ishikawa, S. Suzuki, T. Kotajima, Y. Tanaka, T. Seki, N. Shibata, T. Yamada, T. Fujii, C. Wang, M. Avdeev, K. Nawa, D. Okuyama, T. J. Sato, "Experimental Observation of Long-Range Magnetic Order in Icosahedral Quasicrystals",
      Journal of the American Chemical Society 143 (2021) 19938-19944.

    7. T. Seki, Y. Ikuhara, N. Shibata, "Toward quantitative electromagnetic field imaging by differential-phase-contrast scanning transmission electron microscopy",
      Microscopy 70 (2021) 148-160.

    8. D. G. Hopkinson, T. Seki, N. Clark, R. Chen, Y. Zou, A. Kimura, R. V. Gorbachev, T. Thomson, N. Shibata, S. J. Haigh, "Nanometre imaging of Fe3GeTe2 ferromagnetic domain walls",
      Nanotechnology 32 (2021) 205703.

    9. H. Zeng, T. Takahashi, T. Seki, M. Kanai, G. Zhang, T. Hosomi, K. Nagashima, N. Shibata, T. Yanagida, "Oxygen-Induced Reversible Sn-Dopant Deactivation between Indium Tin Oxide and Single-Crystalline Oxide Nanowire Leading to Interfacial Switching",
      ACS Applied Materials & Interfaces 12 (2020) 52929-52936.

    10. K. Ooe, T. Seki, Y. Ikuhara, N. Shibata, "Ultra-high contrast STEM imaging for segmented/pixelated detectors by maximizing the signal-to-noise ratio",
      Ultramicroscopy 220 (2021) 113133.

    11. Y. O. Murakami, T. Seki, A. Kinoshita, T. Shoji, Y. Ikuhara, N. Shibata, "Magnetic-structure imaging in polycrystalline materials by specimen-tilt series averaged DPC STEM",
      Microscopy 69 (2020) 312-320.

    12. S. Toyama, T. Seki, S. Anada, H. Sasaki, K. Yamamoto, Y. Ikuhara, N. Shibata, "Quantitative electric field mapping of a p–n junction by DPC STEM",
      Ultramicroscopy 216 (2020) 113033.

    13. K. Nakamura, T. Takahashi, T. Hosomi, T. Seki, M. Kanai, G. Zhang, K. Nagashima, N. Shibata, T. Yanagida, "Redox-Inactive CO2 Determines Atmospheric Stability of Electrical Properties of ZnO Nanowire Devices through a Room-Temperature Surface Reaction",
      ACS Applied Materials & Interfaces 11 (2019) 40260-40266.

    14. N. Shibata, Y. Kohno, A. Nakamura, S. Morishita, T. Seki, A. Kumamoto, H. Sawada, T. Matsumoto, S. D. Findlay, Y. Ikuhara, "Atomic resolution electron microscopy in a magnetic field free environment",
      Nature Communications 10 (2019) 2308.

    15. K. Ooe, T. Seki, Y. Ikuhara, N. Shibata, "High contrast STEM imaging for light elements by an annular segmented detector"
      Ultramicroscopy 202 (2019) 148-155.

    16. H. Anzai, T. Takahashi, M. Suzuki, M. Kanai, G. Zhang, T. Hosomi, T. Seki, K. Nagashima, N. Shibata, T. Yanagida, "Unusual Oxygen Partial Pressure Dependence of Electrical Transport of Single-Crystalline Metal Oxide Nanowires Grown by the Vapor–Liquid–Solid Process"
      Nano Letters 19 (2019) 1675-1681.

    17. R. Ishikawa, S.D. Findlay, T. Seki, G. Sanchez-Santlino, Y. Kohno, Y. Ikuhara, N. Shibata, "Direct electric field imaging of graphene defects"
      Nature Communications 9 (2018) 3878.

    18. G. Sánchez-Santolino, N.R. Lugg, T. Seki, R. Ishikawa, S.D. Findlay, Y. Kohno, Y. Kanitani, S. Tanaka, S. Tomiya, Y. Ikuhara, N. Shibata, "Probing the Internal Atomic Charge Density Distributions in Real Space"
      ACS Nano 12 (2018) 8875–8881.

    19. T. Seki, N. Takanashi, E. Abe, "Integrated contrast-treansfer-function for aberration-corrected phase-contrast"
      Ultramicroscopy 194 (2018) 193-198.

    20. T. Seki, Y. Ikuhara, N. Shibata,"Theoretical Framework of Statistical Noise in Scanning Transmission Electron Microscopy"
      Ultramicroscopy 193 (2018) 118-125.

    21. C. Chen, H. Li, T. Seki, D. Yin, G. Sanchez-Santolino, K. Inoue, N. Shibata, Y. Ikuhara,"Direct Determination of Atomic Structure and Magnetic Coupling of Magnetite Twin Boundaries"
      ACS Nano 12 (2018) 2662-2668.

    22. N. Shibata, S.D. Findlay, T. Matsumoto, Y. Kohno, T. Seki, G. Sánchez-Santolino, Y. Ikuhara, "Direct Visualization of Local Electromagnetic Field Structures by Scanning Transmission Electron Microscopy"
      Accounts of Chemical Research 50 (2017) 1502.

    23. A.Ishizuka, M. Oka, T. Seki, N. Shibata, K. Ishizuka,"Boundary-artifact-free determination of potential distribution from differential phase contrast signals"
      Microscopy 66 (2017) 397-405.

    24. T. Seki, G.S. Santolino, R. Ishikawa, S.D. Findlay, Y. Ikuhara, N. Shibata, "Quantitative electric field mapping in thin specimens using a segmented detector: revisiting the transfer function for differential phase contrast"
      Ultramicroscopy 182 (2017) 258.

    25. H. Anzai, M. Suzuki, K. Nagashima, M. Kanai, Z. Zhu, Y. He, M. Boudot, G. Zhang, T. Takahashi, K. Kanemoto, T.Seki, N. Shibata, T. Yanagida, "True Vapor–Liquid–Solid Process Suppresses Unintentional Carrier Doping of Single Crystalline Metal Oxide Nanowires"
      Nano Letters 17 (2017) 4698.

    26. N. Shibata, T. Seki, G.S. Santolino, S.D. Findlay, Y. Kohno, T. Matsumoto, R. Ishikawa, Y. Ikuhara, "Electric field imaging of single atoms"
      Nature Communications 8 (2017) 15631.

    27. T. Seki, E. Abe, "Local cluster symmetry of a highly ordered quasicrystalline Al58Cu26Ir16 extracted through multivariate analysis of STEM images",
      Microscopy 64 (2015) 241.

    Review Articles

    1. T. Seki, Y. Kohno, Y. Ikuhara, N. Shibata, "Atomic-scale Magnetic Field Imaging by Scanning Transmission Electron Microscopy",
      固体物理 58 (2023) 21-27.

    2. Y. Kohno, T. Seki, S. Morishita, N. Shibata, "Development of an Atomic-Resolution Magnetic-Field-Free Electron Microscope and Observation of Atomic Magnetic Fields",
      Kenbikyo 57 (2022) 131-138.

    3. B. Feng, J. Wei, R. Ishikawa, T. Seki, N. Shibata, Y. Ikuhara, "Crystal Defect Core Studied by Advanced Electron Microscopy",
      Materia Japan 61 (2022) 640-644.

    4. K. Ooe, T. Seki, Y. Kohno, A. Nakamura, Y. Ikuhara, N. Shibata, "Low-dose Atomic-resolution Imaging Using OBF STEM",
      Kenbikyo 57 (2022) 49-53.

    5. S. Toyama, T. Seki, Y. Kanitani, S. Tomiya, Y. Ikuhara, N. Shibata, "The Observation of Local Electric Fields in GaN/AlGaN/InGaN Multi-heterostructures by Differential Phase Contrast STEM",
      IEEJ Transactions on Electronics, Information and Systems 142 (2022) 367-372.

    6. T. Seki, G. Sánchez-Santolino, R.Ishikawa, Y. Ikuhara, N. Shibata, "Theory of Atomic-Resolution Differential Phase Contrast STEM",
      Kenbikyo 52 (2017) 8.

    7. E. Abe, D. Egusa, R. Ishikawa and T. Seki, "Ultrahigh-Resolution STEM Analysis of Complex Compounds",
      JEOL News 45 (2010) 20.

    Conference Proceedings

    1. S. Findlay, L. Allen, H. Brown, Z. Chen, J. Ciston, Y. Ikuhara, R. Ishikawa, C. Ophus, G. Sánchez-Santolino, T. Seki, N. Shibata, M. Weyland, "Phase-Contrast-Based Structure Retrieval Methods in Atomic Resolution Scanning Transmission Electron Microscopy – When They Hold and When They Don't",
      Microscopy and Microanalysis 26 (2020) 442-443.

    2. Y. O. Murakami, T. Seki, A. Kinoshita, T. Shoji, Y. Ikuhara, N. Shibata, "New Magnetic Structure Imaging Techniques in Polycrystalline Materials by DPC STEM",
      Microscopy, 68, (2019), i36..

    3. T. Seki, Y. Ikuhara, N. Shibata, "Iterative Algorithm of Atomic Potential Reconstruction Based on DPC Signal from Thick Specimens",
      Microscopy and Microanalysis 25 (2019) 60-61.

    4. K. Ooe, T. Seki, Y. Ikuhara, N. Shibata, "Light Element Imaging Technique at Low Dose Condition by Processing Simultaneously Obtained STEM Images Using a Segmented Detector",
      Microscopy and Microanalysis 25 (2019) 484-485.

    5. T. Seki, Y. Ikuhara, N. Shibata, "Iterative Potential Reconstruction Method based on DPC signal from thick specimens",
      AMTC Letters 6 (2019) 46-47.

    6. K. Ooe, T. Seki, Y. Ikuhara, N. Shibata, "Low Dose STEM Imaging Technique for Light Element Atoms by Processing Images Simultaneously Obtained by a Segmented Detector",
      AMTC Letters 6 (2019) 25-27.

    7. S. Toyama, T. Seki, H. Sasaki, Y. Ikuhara, N. Shibata, "Electric field quantification method for a p-n junction by DPC STEM",
      AMTC Letters 6 (2019) 20-21.

    8. Y. Murakami, T. Seki, A. Kinoshita, T. Shoji, Y. Ikuhara, N. Shibata, "Development of Magnetic Structure Imaging Techniques in Polycrystalline Materials by DPC STEM",
      AMTC Letters 6 (2019) 48-49.

    9. T. Seki, G.S. Santolino, R. Ishikawa, Y. Ikuhara, N. Shibata, "Quantitative Relation Between Differential Phase Contrast Images Obtained by Segmented and Pixelated Detectors"
      Microscopy and Microanalysis 23 (2017) 440.

    10. A. Ishizuka, M. Oka, K. Ishizuka, T. Seki, N. Shibata, "Numerical Procedures to determine Potential Distribution from Electronic Field Vectors observed in Differential Phase Contrast (DPC) imaging",
      Microscopy and Microanalysis 23 (2017) 34-35.

    11. G. Sanchez-Santolino, T. Seki, N. Lugg, R. Ishikawa, D. J. Taplin, S. D. Findlay, Y. Ikuhara, N. Shibata, "Quantitative Atomic Resolution Differential Phase Contrast Imaging Using a Segmented Area All Field Detector",
      Microscopy and Microanalysis 22 (2016) 504-505.

    12. N. Shibata, S. Findlay, T. Matsumoto, T. Seki, G. Sánchez-Santolino, Y. Kohno, H. Sawada, H. Sasaki, Y. So, R. Ishikawa, Y. Ikuhara, "Direct Electromagnetic Structure Observation by Aberration-corrected Differential Phase Contrast Scanning Transmission Electron Microscopy",
      Microscopy and Microanalysis 22 (2016) 906-907.

    13. G. Sanchez-Santolino, T. Seki, N.R. Lugg, R. Ishikawa, D.J. Taplin, S.D. Findlay, Y. Ikuhara, N. Shibata "Characterization of Electromagnetic Fields by Atomic Resolution Differential Phase Contrast Scanning Transmission Electron Microscopy",
      AMTC Letters 5 (2016) 242-243.

    14. D. J. Taplin, R. Ishikawa, T. Seki, H. Sawada, M. Weyland, N. Shibata, S. D. Findlay, "Differential Phase Contrast Imaging using a Segmented Detector",
      AMTC Letters 5 (2016) 24-25.

    15. T. Seki, E. Abe, "Direct observations of local electronic states in an Al-based quasicrystal by STEM-EELS",
      Microscopy 63 (2014) i17.

    16. T. Seki, E. Abe and S.J. Pennycook, "Quantitative Analysis of Point Defects in an Ideal Quasicrystal with Aberration- Corrected STEM and First-Principles Calculations”,
      AMTC Letters 2 (2010) 194.

    17. E. Abe, T. Seki, S. Pennycook, "Quantitative Analysis of Point Defects in an Ideal Quasicrystal by Aberration-Corrected Z-Contrast STEM",
      Microscopy and Microanalysis 15 (2009) 772-773.

    Invited Talks

    1. (Domestic) 関岳人, 「DPC STEMによる機能コアの高分解能電磁場観察」
      新学術領域研究「機能コアの材料科学」若手講演会, Augast 1, 2023.

    2. T. Seki, N. Shibata, "Advanced Phase Imaging in Scanning Transmission Electron Microscopy"
      International Union of Microbeam Analysis Societies, June 15, 2023.

    3. T. Seki, N. Shibata, "Direct Electromagnetic Field Imaging at Defects by Differential Phase Contrast Scanning Transmission Electron Microscopy"
      4th Japan-Canada Microscopy Societies Workshop, June 11, 2023.

    4. (Domestic) 関岳人, 「分割型検出器を用いたSTEM法の開発と応用 」
      日本顕微鏡学会関東支部講演会, March 7, 2023.

    5. (Domestic) 関岳人, 「無磁場原子分解能STEMによる原子・磁気構造解析」
      日本顕微鏡学会超高分解能顕微鏡法分科会, March 3, 2023.

    6. (Domestic) 関岳人, 「走査透過電子顕微鏡法の開発とハイパーマテリアルへの応用 」
      第27回ハイパーマテリアルセミナー, January 12, 2023.

    7. T. Seki, Y. Ikuhara, N. Shibata, "Theory and Applications of Phase Imaging in STEM Using a Segmented Detector"
      Annual Meeting of the Japanese Society of Microscopy May 10, 2022.

    8. T. Seki, K. Ooe, Y. Ikuhara, N. Shibata, "Ultra-high contrast imaging in scanning transmission electron microscopy"
      Monash/Melbourne Imaging and Optical Physics Seminar, July 13, 2021

    9. (Domestic) T. Seki, K. Ooe, Y. Ikuhara, N. Shibata, "Theory and Applications of STEM Phase Imaging"
      Annual Meeting of the Japanese Society of Microscopy, June 16, 2021.

    10. (Domestic) T. Seki, Y. Ikuhara, N. Shibata, "Theory and Applications of STEM Phase Imaging"
      63rd JSM Symposium, November 20, 2020.

    11. (Domestic) T. Seki, G. Sánchez-Santolino,R. Ishikawa, S.D. Findlay, Y. Ikuhara, N. Shibata, "Basics of electromagnetic field quantification by DPC"
      日本顕微鏡学会分析電子顕微鏡討論会, September 3, 2019.

    12. (Domestic) T. Seki, Y. Ikuhara, N. Shibata, "Iterative Potential Reconstrcution by DPC STEM"
      Annual Meeting of the Japanese Society of Microscopy, May 31, 2018.

    13. (Domestic) T. Seki, G. Sánchez-Santolino,R. Ishikawa, S.D. Findlay, Y. Ikuhara, N. Shibata, "Current Status and Future Prospects of Electromagnetic Field Quantification by Differential Phase Contrast"
      日本顕微鏡学会超高分解能顕微鏡法分科会研究会, February 24, 2018 .

    Awards

    1. Mar.2023, AnPang Tsai Award, Quasicrystals meeting

    2. May 2022, Encouragement Award, The Japanese Society of Microscopy

    3. March 2021, Kazato Research Encouragement Prize, Kazato Research Foundation

    4. May 2019, Award for Scientific Paper (Fundamentals), The Japanese Society of Microscopy.

    5. May 2017, Award for Scientific Paper (Materials), The Japanese Society of Microscopy.

    6. Sep. 2013, Best Poster Prize, 12th International Conference on Quasicrystals.

    7. AMay 2011, Young Scientist Award, The 6th Asian International Workshop on Quasicrystal.


    Patents

    1. Patent Application JP 2023-101824 MEASUREMENT METHOD BY MEANS OF SCANNING TRANSMISSION ELECTRON MICROSCOPE, SCANNING TRANSMISSION ELECTRON MICROSCOPE SYSTEM, AND PROGRAM, Takehito Seki, Naoya Shibata, Mitsuru Nogami, Kousuke Ooe, Yuichi Ikuhara

    2. Patent Publication JP 2021-077523 OBSERVATION METHOD BY MEANS OF SCANNING TRANSMISSION ELECTRON MICROSCOPE, SCANNING TRANSMISSION ELECTRON MICROSCOPE SYSTEM, AND PROGRAM, Naoya Shibata, Takehito Seki, Kousuke Ooe, Yuichi Ikuhara