| アイテムタイプ |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2024-07-24 |
| タイトル |
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タイトル |
Collective dynamics of liquid sulphur across the polymerisation transition temperature probed by inelastic x-ray scattering |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
| 著者 |
Hosokawa Shinya
Katayama Yoshinori
TsuTsui Satoshi
Baron Alfred Q. R.
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| 抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
Inelastic x-ray scattering (IXS) experiments on liquid sulphur were carried out below (140?C) and above (180?C) the polymerisation temperature T_lambda of about 159?C to investigate changes in collective dynamics of this unique liquid exhibiting a liquid-liquid transition. As were reported earlier, broad longitudinal acoustic excitation signals were observed at both the temperatures, and only the width of the quasielastic peaks slightly decreases when the temperature crosses the transition. A model analysis was performed by using a generalised Langevin formalism with a memory function having a thermal and two viscoelastic decay channels with a help of a simple sparse modelling, from which large positive deviations from the hydrodynamic sound velocity by 51-54% was observed. The fast viscoelastic relaxation rate Tau_μ are close to the correlation times of intermolecular stretching and bending motions of local sulphur connections in either ring or chain structures, which is similar to those of other molecular liquids. The small contrasts in the IXS spectra across the lambda transition result in only large changes in the slow viscoelastic decay rate of Tau_alpha of the memory function. The Tau_alpha value at 140?C matches well with the mixed internal/external torsional modes of S8 molecules, whereas that at 180?C has no corresponding molecular motion mode. The kinematic viscosity values at the Q → 0 limit are much smaller than the minimum values of macroscopic shear viscosity, indicating that large Q changes of the relaxation dynamics are expected in the GHz and MHz excitation regimes. |
| 書誌情報 |
Journal of Physics: Condensed Matter
巻 36,
p. 425102,
発行日 2024-07
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| 出版者 |
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出版者 |
IOP Publishing |
| ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
1361-648X |
| DOI |
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識別子タイプ |
DOI |
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関連識別子 |
10.1088/1361-648X/ad493f |
