Gumann, Sina ; Nestle, Nikolaus ; Liebau-Kunzmann, Verena ; Riedel, Ralf (2007)
Investigations of Li-containing SiCN(O) ceramics via 7Li MAS NMR.
In: Solid State Nuclear Magnetic Resonance, 31 (2)
doi: 10.1016/j.ssnmr.2007.02.003
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Lithium-containing silicon (oxy)carbonitride ceramics (SiCN(O):Li) were synthesized via precursor-to-ceramic-transformation of Li-containing (poly)silazanes. The precursors were obtained by lithiation of 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane with n-butyllithium and by reaction of a commercial poly(organosilazane) VL20® with metallic lithium. The annealing treatment was carried out at temperatures between 200 and 1400 °C in argon (ΔT=200 °C) and yielded Li-containing silicon (oxy)carbonitride. X-ray powder diffraction revealed that the resulting SiCN(O):Li ceramics were basically amorphous up to temperatures of 1000 °C and formed LiSi2N3, graphite and silicon carbide as crystalline phases at higher temperatures. 7Li MAS NMR spectroscopy was carried out to investigate the structure of the Li-containing phases and to study the reaction path of metallic Li with polysilazane. Based on the NMR spectra, there is almost no difference found in the chemical shift of the SiCN(O):Li ceramics obtained at different temperatures. Accordingly, Li is assigned to be mainly coordinated to N and O present as contaminant element. Relaxation time measurements showed that the most mobile Li+ species seems to be present in the product obtained in the pyrolysis temperature range between 600 and 1000 °C.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2007 |
| Autor(en): | Gumann, Sina ; Nestle, Nikolaus ; Liebau-Kunzmann, Verena ; Riedel, Ralf |
| Art des Eintrags: | Bibliographie |
| Titel: | Investigations of Li-containing SiCN(O) ceramics via 7Li MAS NMR |
| Sprache: | Englisch |
| Publikationsjahr: | April 2007 |
| Verlag: | Elsevier |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Solid State Nuclear Magnetic Resonance |
| Jahrgang/Volume einer Zeitschrift: | 31 |
| (Heft-)Nummer: | 2 |
| DOI: | 10.1016/j.ssnmr.2007.02.003 |
| Kurzbeschreibung (Abstract): | Lithium-containing silicon (oxy)carbonitride ceramics (SiCN(O):Li) were synthesized via precursor-to-ceramic-transformation of Li-containing (poly)silazanes. The precursors were obtained by lithiation of 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane with n-butyllithium and by reaction of a commercial poly(organosilazane) VL20® with metallic lithium. The annealing treatment was carried out at temperatures between 200 and 1400 °C in argon (ΔT=200 °C) and yielded Li-containing silicon (oxy)carbonitride. X-ray powder diffraction revealed that the resulting SiCN(O):Li ceramics were basically amorphous up to temperatures of 1000 °C and formed LiSi2N3, graphite and silicon carbide as crystalline phases at higher temperatures. 7Li MAS NMR spectroscopy was carried out to investigate the structure of the Li-containing phases and to study the reaction path of metallic Li with polysilazane. Based on the NMR spectra, there is almost no difference found in the chemical shift of the SiCN(O):Li ceramics obtained at different temperatures. Accordingly, Li is assigned to be mainly coordinated to N and O present as contaminant element. Relaxation time measurements showed that the most mobile Li+ species seems to be present in the product obtained in the pyrolysis temperature range between 600 and 1000 °C. |
| Freie Schlagworte: | Silazanes, SiCN(O), 7Li MAS NMR spectroscopy |
| Zusätzliche Informationen: | SFB 505 Cooperation A4, B5 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe DFG-Sonderforschungsbereiche (inkl. Transregio) DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche 05 Fachbereich Physik 05 Fachbereich Physik > Institut für Angewandte Physik Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese > Teilprojekt A4: Neue Funktionskeramiken durch Anionensubstitution in oxidischen Systemen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > B - Charakterisierung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > B - Charakterisierung > Teilprojekt B5: Modellversuche zur Wechselwirkung ferroelektrischer Domänen mit Punktdefekten und deren Agglomeraten |
| Hinterlegungsdatum: | 17 Apr 2012 09:21 |
| Letzte Änderung: | 30 Jan 2019 11:33 |
| PPN: | |
| Sponsoren: | For financial support we thank the German Science Foundation, SFB 595 “Electric Fatigue in Functional Materials”. |
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