Rosenburg, Felix ; Ionescu, Emanuel ; Nicoloso, Norbert ; Riedel, Ralf (2018)
High-Temperature Raman Spectroscopy of Nano-Crystalline Carbon in Silicon Oxycarbide.
In: Materials, 11 (1)
doi: 10.3390/ma11010093
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
The microstructure of segregated carbon in silicon oxycarbide (SiOC), hot-pressed at T = 1600 °C and p = 50 MPa, has been investigated by VIS Raman spectroscopy (λ = 514 nm) within the temperature range 25–1000 °C in air. The occurrence of the G, D’ and D bands at 1590, 1620 and 1350 cm−1, together with a lateral crystal size La < 10 nm and an average distance between lattice defects LD ≈ 8 nm, provides evidence that carbon exists as nano-crystalline phase in SiOC containing 11 and 17 vol % carbon. Both samples show a linear red shift of the G band up to the highest temperature applied, which is in agreement with the description of the anharmonic contribution to the lattice potential by the modified Tersoff potential. The temperature coefficient χG = −0.024 ± 0.001 cm−1/°C is close to that of disordered carbon, e.g., carbon nanowalls or commercial activated graphite. The line width of the G band is independent of temperature with FWHM-values of 35 cm−1 (C-11) and 45 cm−1 (C-17), suggesting that scattering with defects and impurities outweighs the phonon-phonon and phonon-electron interactions. Analysis of the Raman line intensities indicates vacancies as dominating defects.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Rosenburg, Felix ; Ionescu, Emanuel ; Nicoloso, Norbert ; Riedel, Ralf |
| Art des Eintrags: | Bibliographie |
| Titel: | High-Temperature Raman Spectroscopy of Nano-Crystalline Carbon in Silicon Oxycarbide |
| Sprache: | Englisch |
| Publikationsjahr: | 9 Januar 2018 |
| Verlag: | MDPI |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Materials |
| Jahrgang/Volume einer Zeitschrift: | 11 |
| (Heft-)Nummer: | 1 |
| DOI: | 10.3390/ma11010093 |
| URL / URN: | https://doi.org/10.3390/ma11010093 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | The microstructure of segregated carbon in silicon oxycarbide (SiOC), hot-pressed at T = 1600 °C and p = 50 MPa, has been investigated by VIS Raman spectroscopy (λ = 514 nm) within the temperature range 25–1000 °C in air. The occurrence of the G, D’ and D bands at 1590, 1620 and 1350 cm−1, together with a lateral crystal size La < 10 nm and an average distance between lattice defects LD ≈ 8 nm, provides evidence that carbon exists as nano-crystalline phase in SiOC containing 11 and 17 vol % carbon. Both samples show a linear red shift of the G band up to the highest temperature applied, which is in agreement with the description of the anharmonic contribution to the lattice potential by the modified Tersoff potential. The temperature coefficient χG = −0.024 ± 0.001 cm−1/°C is close to that of disordered carbon, e.g., carbon nanowalls or commercial activated graphite. The line width of the G band is independent of temperature with FWHM-values of 35 cm−1 (C-11) and 45 cm−1 (C-17), suggesting that scattering with defects and impurities outweighs the phonon-phonon and phonon-electron interactions. Analysis of the Raman line intensities indicates vacancies as dominating defects. |
| Freie Schlagworte: | polymer-derived ceramics, Raman spectroscopy, anharmonicity, carbon, defects |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe |
| Hinterlegungsdatum: | 15 Jan 2018 09:10 |
| Letzte Änderung: | 22 Nov 2023 10:03 |
| PPN: | |
| Sponsoren: | The authors gratefully acknowledge financial support by theDeutsche Forschungsgemeinschaft |
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| Suche nach Titel in: | TUfind oder in Google |
Verfügbare Versionen dieses Eintrags
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High-Temperature Raman Spectroscopy of Nano-Crystalline Carbon in Silicon Oxycarbide. (deposited 21 Nov 2023 13:45)
- High-Temperature Raman Spectroscopy of Nano-Crystalline Carbon in Silicon Oxycarbide. (deposited 15 Jan 2018 09:10) [Gegenwärtig angezeigt]
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