Abstract
High-pressure Raman scattering measurements for the high-pressure phase III of methane hydrate (MH-III, filled ice structure) have been performed at pressures up to 25 GPa and at 296 K. We have observed the O-H stretching Raman signal in the MH-III phase by growing the MH-III crystals over several days at 1.9 GPa. The O-H stretching vibrational peak in the MH-III phase shows negative pressure dependence indicative of hydrogen bond and disappears above 14 GPa. The symmetrization pressure of hydrogen bond in the MH-III phase is estimated to be about 45 GPa from the pressure dependence of the O-H stretching Raman frequency, which is consistent with the previous theoretical prediction.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
