Hiroki Kobayashi
I am working as...
- Chercheur invité (Guest Researcher) at Institut de minéralogie, de physique des matériaux et de cosmochimie, Sorbonne University, France (Feb 2025–, Physique des systèmes simples en conditions extrêmes (PHYSIX) group, hosted by Dr Stephan Klotz)
- PhD student at Geochemical Research Centre (Kagi/Komatsu Group), Graduate School of Science, the University of Tokyo, Japan
Research Interest
High-pressure, water, ice, aqueous solutions, phase transition, crystallography, experimental mineral physics and chemistry
Research Experience
Neutron diffraction, x-ray diffraction, Raman spectroscopy, differential scanning calorimetry
Software Skills: Click here to Show
Languages
English (upper intermediate) & Japanese (native)
Research History
- Feb. 2025 – current. Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France. Chercheur invité (Invited Researcher). Hosted by Dr. Stephan Klotz.
- Apr. 2021 – current. Geochemical Research Center, Graduate School of Science, The University of Tokyo. BSc (Mar. 2022), MSc (Mar. 2024), PhD (Apr. 2024 –). Supervised by Prof. Hiroyuki Kagi and Kazuki Komatsu.
Recent news
- I am staying at IMPMC, Sorbonne Univ., Paris, from Feb. 2025 as an invited researcher hosted by Dr Stefan Klotz.
- Experiments at ISIS in September
- Experiments at ILL in October
- Experiments at SOLEIL in October
- I discovered three new phases of ice and their structure arXiv preprint
- We reported weak hydrogen ordering in ice IV H.K. et al., JPCL (2023)
Featured Works
Slightly Hydrogen-Ordered State of Ice IV Evidenced by In-Situ Neutron Diffraction
, Kazuki Komatsu, Hayate Ito, Shinichi Machida, Takanori Hattori, and Hiroyuki Kagi.
The Journal of Physical Chemistry Letters (2023) 14 10664
DOI: 10.1021/acs.jpclett.3c02563
Awards
- Aug. 2025: IUCr Young Scientist Award (for the attendance at ECM35)
- Feb. 2025: Ludo Frevel Crystallography Scholarship Award from International Centre for Diffraction Data (ICDD). "In-depth neutron diffraction study of unusual hydrogen ordering behaviour in ice VI" (2,500 USD)
- Mar. 2024: Graduate School of Science Awards (for MSc studies), UTokyo
- Aug. 2023: CrSJ Travel Award (for the attendance at IUCr2023)
- Mar. 2022: Department of Chemistry Chair Award (for BSc studies), Faculty of Science, UTokyo
Grants
- FY2024. Overseas Challenge Program for Young Researchers (1,400,000 JPY + transportation costs) from Japan Society of Promotion of Science (JSPS). "Precise analysis of the hydrogen-atom distribution in a high-pressure phase of ice by single-crystal neutron diffraction"
- FY2024. Sasakawa Scientific Research Grant from The Japan Science Society (880,000 JPY)
We reported crystallographic evidence for the hydrogen ordering in ice IV by neutron diffraction. It shows discontinuous behaviour at 120 K and Rietveld analysis at the low-T side suggests it is a very weak hydrogen ordering structural transition.