INELASTIC NEUTRON SCATTERING STUDY OF HOST AND GUEST MOLECULAR MOTIONS IN METHANE HYDRATE ...
Methane hydrate has a unique structure that the host water framework forms two kinds of cages, which contain one methane molecule each. Therefore, it has been expected that there may exist three kinds of translational modes of a methane molecule and also the distortion of translational mode of host...
| Main Authors: | , , , , , , , , , |
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| Format: | Text |
| Language: | English |
| Published: |
The University of British Columbia
2008
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.14288/1.0041073 https://doi.library.ubc.ca/10.14288/1.0041073 |
| Summary: | Methane hydrate has a unique structure that the host water framework forms two kinds of cages, which contain one methane molecule each. Therefore, it has been expected that there may exist three kinds of translational modes of a methane molecule and also the distortion of translational mode of host water molecules compared with normal ice. We need information of the host and guest molecular dynamics over the wide momentum and energy transfer region for studying such dynamics. In this study inelastic neutron measurements were carried under 40 K with MARI spectrometer at ISIS in UK, TAS at JRR-3 and CAT at KENS in Japan. For the methane molecular motion we could confirm its freelike rotation by complementary use of MARI and TAS spectra. After the subtraction of the scattering intensity of the rotation evaluated by the free rotation model from the experimental data, three kinds of translation modes were identified at first experimentally. On the experimental spectra there still remains the excess intensity ... |
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