Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure
A 4:1 (volume ratio) methanol–ethanol (ME) mixture and silicone oil are two of the most widely used liquid pressure-transmitting media (PTM) in high-pressure studies. Their hydrostatic limits have been extensively studied using various methods; however, the evolution of the atomic structures associa...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2021-05-01
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| Series: | Matter and Radiation at Extremes |
| Online Access: | http://dx.doi.org/10.1063/5.0044893 |
| _version_ | 1818863748049272832 |
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| author | Xiehang Chen Hongbo Lou Zhidan Zeng Benyuan Cheng Xin Zhang Ye Liu Dazhe Xu Ke Yang Qiaoshi Zeng |
| author_facet | Xiehang Chen Hongbo Lou Zhidan Zeng Benyuan Cheng Xin Zhang Ye Liu Dazhe Xu Ke Yang Qiaoshi Zeng |
| author_sort | Xiehang Chen |
| collection | DOAJ |
| description | A 4:1 (volume ratio) methanol–ethanol (ME) mixture and silicone oil are two of the most widely used liquid pressure-transmitting media (PTM) in high-pressure studies. Their hydrostatic limits have been extensively studied using various methods; however, the evolution of the atomic structures associated with their emerging nonhydrostaticity remains unclear. Here, we monitor their structures as functions of pressure up to ∼30 GPa at room temperature using in situ high-pressure synchrotron x-ray diffraction (XRD), optical micro-Raman spectroscopy, and ruby fluorescence spectroscopy in a diamond anvil cell. No crystallization is observed for either PTM. The pressure dependence of the principal diffraction peak position and width indicates the existence of a glass transition in the 4:1 ME mixture at ∼12 GPa and in the silicone oil at ∼3 GPa, beyond which a pressure gradient emerges and grows quickly with pressure. There may be another liquid-to-liquid transition in the 4:1 ME mixture at ∼5 GPa and two more glass-to-glass transitions in the silicone oil at ∼10 GPa and ∼16 GPa. By contrast, Raman signals only show peak weakening and broadening for typical structural disordering, and Raman spectroscopy seems to be less sensitive than XRD in catching these structural transitions related to hydrostaticity variations in both PTM. These results uncover rich pressure-induced transitions in the two PTM and clarify their effects on hydrostaticity with direct structural evidence. The high-pressure XRD and Raman data on the two PTM obtained in this work could also be helpful in distinguishing between signals from samples and those from PTM in future high-pressure experiments. |
| first_indexed | 2024-12-19T10:20:41Z |
| format | Article |
| id | doaj.art-17266f4c673f4f029b92ee06c86dca7c |
| institution | Directory Open Access Journal |
| issn | 2468-080X |
| language | English |
| last_indexed | 2024-12-19T10:20:41Z |
| publishDate | 2021-05-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | Matter and Radiation at Extremes |
| spelling | doaj.art-17266f4c673f4f029b92ee06c86dca7c2022-12-21T20:26:03ZengAIP Publishing LLCMatter and Radiation at Extremes2468-080X2021-05-0163038402038402-710.1063/5.0044893Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressureXiehang Chen0Hongbo Lou1Zhidan Zeng2Benyuan Cheng3Xin Zhang4Ye Liu5Dazhe Xu6Ke Yang7Qiaoshi Zeng8Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaShanghai Synchrotron Radiation Facility, Shanghai 201800, People’s Republic of ChinaCenter for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of ChinaA 4:1 (volume ratio) methanol–ethanol (ME) mixture and silicone oil are two of the most widely used liquid pressure-transmitting media (PTM) in high-pressure studies. Their hydrostatic limits have been extensively studied using various methods; however, the evolution of the atomic structures associated with their emerging nonhydrostaticity remains unclear. Here, we monitor their structures as functions of pressure up to ∼30 GPa at room temperature using in situ high-pressure synchrotron x-ray diffraction (XRD), optical micro-Raman spectroscopy, and ruby fluorescence spectroscopy in a diamond anvil cell. No crystallization is observed for either PTM. The pressure dependence of the principal diffraction peak position and width indicates the existence of a glass transition in the 4:1 ME mixture at ∼12 GPa and in the silicone oil at ∼3 GPa, beyond which a pressure gradient emerges and grows quickly with pressure. There may be another liquid-to-liquid transition in the 4:1 ME mixture at ∼5 GPa and two more glass-to-glass transitions in the silicone oil at ∼10 GPa and ∼16 GPa. By contrast, Raman signals only show peak weakening and broadening for typical structural disordering, and Raman spectroscopy seems to be less sensitive than XRD in catching these structural transitions related to hydrostaticity variations in both PTM. These results uncover rich pressure-induced transitions in the two PTM and clarify their effects on hydrostaticity with direct structural evidence. The high-pressure XRD and Raman data on the two PTM obtained in this work could also be helpful in distinguishing between signals from samples and those from PTM in future high-pressure experiments.http://dx.doi.org/10.1063/5.0044893 |
| spellingShingle | Xiehang Chen Hongbo Lou Zhidan Zeng Benyuan Cheng Xin Zhang Ye Liu Dazhe Xu Ke Yang Qiaoshi Zeng Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure Matter and Radiation at Extremes |
| title | Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure |
| title_full | Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure |
| title_fullStr | Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure |
| title_full_unstemmed | Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure |
| title_short | Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure |
| title_sort | structural transitions of 4 1 methanol ethanol mixture and silicone oil under high pressure |
| url | http://dx.doi.org/10.1063/5.0044893 |
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