Hiroki Kobayashi

I am...

PhD student at Geochemical Research Centre (Kagi/Komatsu Group), Graduate School of Science, the University of Tokyo.

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

Find me at...

E-mail: hiroki@eqchem.s.u-tokyo.ac.jp

Links: ResearchGate Google Scholar

Address: Room 2702, 7F, Chemistry West Building, School of Science, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.

Education history

  • 2024 – current. PhD student at Department of Chemistry, the University of Tokyo; supervised by Prof. Hiroyuki Kagi and Kazuki Komatsu.
  • 2022 - current. World-leading Innovative Graduate Study program for Materials Research, Information, and Technology (MERIT-WINGS), the University of Tokyo; advisory supervisor: Prof. Zenji Hiroi.
  • 2022 - 2024. Master course student at Department of Chemistry, the University of Tokyo; supervised by Prof. Hiroyuki Kagi and Kazuki Komatsu.
    MSc from the University of Tokyo
  • 2021 - 2022. Undergraduate student at Geochemical Research Centre, the University of Tokyo; Supervised by Prof. Hiroyuki Kagi and Kazuki Komatsu.
    BSc from the University of Tokyo
  • I've been studying the hydrogen ordering behaviour of high-pressure ice phases. My first research topic was H-ordering behaviour of ice IV, which has been published: HK et al., JPCL (2023). In 2022, I also started to study the phase transition of ice VI families (namely VI, XV, and XIX) using calorimetric and crystallographic methods.
  • Throughout the ice-IV project, where I performed lots of crystallisation experiments of amorphous ice, I got interested in how, when, and where such metastable ice phases form – this is one of my current projects.

Forthcoming events

  • I will stay at Dr. Stefan Klotz's group in Sorbonne Univ., Paris, from Feb. 2025 as a visiting researcher.

Featured Works

❄️ Slightly Hydrogen-Ordered State of Ice IV Evidenced by In-Situ Neutron Diffraction

Hiroki Kobayashi*, Kazuki Komatsu, Hayate Ito, Shinichi Machida, Takanori Hattori, and Hiroyuki Kagi.

The Journal of Physical Chemistry Letters (2023) 14 10664
https://doi.org/10.1021/acs.jpclett.3c02563

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.

Awards

  1. Mar. 2024. 東京大学理学系研究科研究奨励賞, 理学系研究科総代 (Graduate School of Science Awards for Master's studies, UTokyo).
  2. Aug. 2023. CrSJ Travel Award (fund for the attendance at IUCr2023).
  3. Dec. 2022. Best presentation award, 6th Neutron and Muon School. "Observations of phonons by inelastic neutron scattering"
  4. Mar. 2022. 東京大学理学部化学科長賞 (Department of Chemistry Chair Award, Faculty of Science, UTokyo).