The intrinsic temperature-dependent Raman spectra of graphite in the temperature range from 4K to 1000K
Autor: | He-Nan Liu, Miao-Ling Lin, Ping-Heng Tan, Xin Cong |
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Rok vydání: | 2019 |
Předmět: |
Materials science
Silicon Phonon chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention Condensed Matter::Materials Science symbols.namesake law General Materials Science Graphite Physics::Chemical Physics Condensed matter physics Graphene Anharmonicity General Chemistry Atmospheric temperature range 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry symbols 0210 nano-technology Raman spectroscopy Raman scattering |
Zdroj: | Carbon. 152:451-458 |
ISSN: | 0008-6223 |
Popis: | Temperature-dependent (T-dependent) Raman scattering can provide valuable informations on thermal properties, phonon anharmonicity and electron-phonon coupling of graphene-based materials. Graphene are found to exhibit extrinsic T-dependent Raman behavior at low temperature in vacuum or N2 gas, showing a behavior of heavily doped graphene. To obtain intrinsic properties of graphene-based materials, we focused on the comparative T-dependent Raman study on graphite and silicon in the temperature range of 4 K∼1000 K by different excitation lasers and different hot-stages or cryogenic stations. In contrast to the monotonic increase of full width at half maximum (FWHM) with temperature for the Si mode in silicon, FWHM for the G mode in graphite exhibits a minimum when T ∼ 700 K , which can be explained by the contributions from phonon anharmonicity and electron-phonon coupling. The result shows that the previous theoretical works underestimate the contribution from phonon anharmonicity above ∼ 600 K. The electron-phonon coupling strength of 0.026 is revealed, smaller than that of graphene. The peak position of G peak of graphite shows a nonlinear decrease with increasing temperature, which agrees well with the previous theoretical calculation. Our results find that the contribution of phonon anharmonicity to both peak position and FWHM is more prominent for the G mode in graphite than the Si mode in silicon. |
Databáze: | OpenAIRE |
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