High-pressure Raman and Brillouin studies of single crystalline gas hydrates
Methane hydrate (MH) and argon hydrate (AH) single crystals were synthesized in a diamond anvil cell to investigate their intrinsic high-pressure properties by visual observation and in situ Raman and Brillouin-scattering measurements. Single crystalline MH shows clearly two phase transitions at P =...
Published in: | Canadian Journal of Physics |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
2003
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/p03-026 http://www.nrcresearchpress.com/doi/pdf/10.1139/p03-026 |
id |
crcansciencepubl:10.1139/p03-026 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/p03-026 2023-12-17T10:33:24+01:00 High-pressure Raman and Brillouin studies of single crystalline gas hydrates Shimizu, H 2003 http://dx.doi.org/10.1139/p03-026 http://www.nrcresearchpress.com/doi/pdf/10.1139/p03-026 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Physics volume 81, issue 1-2, page 127-133 ISSN 0008-4204 1208-6045 General Physics and Astronomy journal-article 2003 crcansciencepubl https://doi.org/10.1139/p03-026 2023-11-19T13:38:17Z Methane hydrate (MH) and argon hydrate (AH) single crystals were synthesized in a diamond anvil cell to investigate their intrinsic high-pressure properties by visual observation and in situ Raman and Brillouin-scattering measurements. Single crystalline MH shows clearly two phase transitions at P =0.9 and 1.9 GPa in its crystalline shape and state under a microscope, and in the change in its Raman spectra of CH stretching vibrations of guest CH 4 molecules. The first determination of the elastic properties in MH sI phase has revealed that MH is about 10% softer than the most common ice Ih, which is accounted for by MH's void-rich and open structures. For a single-crystal AH, we have observed two phase transitions from AH-I (sII) to AH-II at about P =0.65 GPa and from AH-II to AH-III at P =1.02 GPa. The breakdown of the cage structure in AH-III was confirmed by the disappearance of the OH stretching mode of host H 2 O lattices. The possibility of Ar double occupancy in the large cages of sII and higher pressure phases is investigated by the low-frequency Raman peak observed around 120 ~ 140 cm 1 in view of recent MD calculations. PACS Nos.: 62.30+d, 62.50+p, 62.65+k, 64.70-p, 78.30-j, 78.35+c Article in Journal/Newspaper Methane hydrate Canadian Science Publishing (via Crossref) Anvil ENVELOPE(-64.267,-64.267,-65.239,-65.239) Canadian Journal of Physics 81 1-2 127 133 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Physics and Astronomy |
spellingShingle |
General Physics and Astronomy Shimizu, H High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
topic_facet |
General Physics and Astronomy |
description |
Methane hydrate (MH) and argon hydrate (AH) single crystals were synthesized in a diamond anvil cell to investigate their intrinsic high-pressure properties by visual observation and in situ Raman and Brillouin-scattering measurements. Single crystalline MH shows clearly two phase transitions at P =0.9 and 1.9 GPa in its crystalline shape and state under a microscope, and in the change in its Raman spectra of CH stretching vibrations of guest CH 4 molecules. The first determination of the elastic properties in MH sI phase has revealed that MH is about 10% softer than the most common ice Ih, which is accounted for by MH's void-rich and open structures. For a single-crystal AH, we have observed two phase transitions from AH-I (sII) to AH-II at about P =0.65 GPa and from AH-II to AH-III at P =1.02 GPa. The breakdown of the cage structure in AH-III was confirmed by the disappearance of the OH stretching mode of host H 2 O lattices. The possibility of Ar double occupancy in the large cages of sII and higher pressure phases is investigated by the low-frequency Raman peak observed around 120 ~ 140 cm 1 in view of recent MD calculations. PACS Nos.: 62.30+d, 62.50+p, 62.65+k, 64.70-p, 78.30-j, 78.35+c |
format |
Article in Journal/Newspaper |
author |
Shimizu, H |
author_facet |
Shimizu, H |
author_sort |
Shimizu, H |
title |
High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
title_short |
High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
title_full |
High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
title_fullStr |
High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
title_full_unstemmed |
High-pressure Raman and Brillouin studies of single crystalline gas hydrates |
title_sort |
high-pressure raman and brillouin studies of single crystalline gas hydrates |
publisher |
Canadian Science Publishing |
publishDate |
2003 |
url |
http://dx.doi.org/10.1139/p03-026 http://www.nrcresearchpress.com/doi/pdf/10.1139/p03-026 |
long_lat |
ENVELOPE(-64.267,-64.267,-65.239,-65.239) |
geographic |
Anvil |
geographic_facet |
Anvil |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Canadian Journal of Physics volume 81, issue 1-2, page 127-133 ISSN 0008-4204 1208-6045 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/p03-026 |
container_title |
Canadian Journal of Physics |
container_volume |
81 |
container_issue |
1-2 |
container_start_page |
127 |
op_container_end_page |
133 |
_version_ |
1785587376265887744 |