Inelastic neutron scattering study on boson peaks of imidazolium-based ionic liquids
| Autor: | Andrey Podlesnyak, Yosuke Moriya, Osamu Yamamuro, Georg Ehlers, Maiko Kofu, Yasuhiro Inamura |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Radius Inelastic scattering Condensed Matter Physics Inelastic neutron scattering Atomic and Molecular Physics and Optics Neutron spectroscopy Ion Electronic Optical and Magnetic Materials Materials Chemistry Physics::Chemical Physics Atomic physics Physical and Theoretical Chemistry Glass transition Excitation Spectroscopy Boson |
| Zdroj: | Journal of Molecular Liquids. 210:164-168 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2015.07.021 |
| Popis: | Low energy excitations of 1-alkyl-3-methylimidazolium ionic liquids (ILs) have been investigated by means of neutron spectroscopy. In the spectra of inelastic scattering, a broad excitation peak referred to as a “boson peak” appeared at 1–3 meV in all of the ILs measured. The intensity of the boson peak was enhanced at the Q positions corresponding to the diffraction peaks, reflecting the in-phase vibrational nature of the boson peak. Furthermore the boson peak energy (EBP) was insensitive to the length of the alkyl-chain but changed depending on the radius of the anion. From the correlation among EBP, the anion radius, and the glass transition temperature Tg, we conclude that both EBP and Tg in ILs are predominantly governed by the inter-ionic Coulomb interaction which is less influenced by the alkyl-chain length. We also found that the EBP is proportional to the inverse square root of the molecular weight as observed in molecular glasses. |
| Databáze: | OpenAIRE |
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