Intercalation of solid hydrogen into graphite under pressures Journal Article uri icon

DCO ID 11121/7121-4146-6501-4630-CC

is Contribution to the DCO

  • YES

year of publication

  • 2016

abstract

  • We present the Raman spectral evidence of pressure-induced intercalation of solid hydrogen into graphite to 60 GPa. The intercalation is evident by the emergence of two characteristic Raman bands of hydrogen (νo1 and νo2), which appear upon the solidification of hydrogen and disappear as all sp2-hybridized graphitic carbons convert to sp3-hybridized hexagonal diamond at 57 GPa. The νo1 and νo2 frequencies of intercalated hydrogen, 4250 and 4270 cm−1 at 10 GPa, are substantially higher than the νo of bulk hydrogen, 4228 cm−1 at the same pressure, indicating the presence of strong repulsive interactions between intercalated hydrogen molecules and graphite layers and, thereby, strong internal chemical pressures. Based on the spectral blue shift of intercalated hydrogen vibrons, we estimate the internal pressure to be ∼1 GPa at 10 GPa and ∼10 GPa at 50 GPa.

volume

  • 109

issue

  • 5