Near-infrared spectra of H2O under high pressure and high temperature: Implications for a transition from proton tunneling to hopping states

Naoki Noguchi, Kazuki Komatsu, Ayako Shinozaki, Keiji Shinoda, Hiroyuki Kagi

    Research output: Contribution to journalArticlepeer-review

    2 Citations (Scopus)

    Abstract

    The nature of protons in ice VII up to 368 °C and 16 GPa was investigated with synchrotron near-infrared spectroscopy. The absorption band of the first OH stretching overtone mode divided into doublet peaks above 5 GPa at room temperature, suggesting that proton tunneling occurs at the overtone level. As the temperature increased, the doublet peaks gradually reduced to a singlet. This result implies that thermally activated protons hop between the two potential minima along the oxygen-oxygen axis. A pressure-temperature diagram for the proton state was constructed from the changing band shape of the overtone mode.

    Original languageEnglish
    Pages (from-to)509-513
    Number of pages5
    JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
    Volume133
    DOIs
    Publication statusPublished - Dec 10 2014

    Keywords

    • High pressure and high temperature
    • Ice
    • Near-infrared spectroscopy
    • Proton hopping
    • Proton tunneling

    ASJC Scopus subject areas

    • Analytical Chemistry
    • Atomic and Molecular Physics, and Optics
    • Instrumentation
    • Spectroscopy

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