Wen, Qingbo ; Yu, Zhaoju ; Xu, Yeping ; Lu, Yan ; Fasel, Claudia ; Morita, Koji ; Guillon, Olivier ; Buntkowsky, Gerd ; Ionescu, Emanuel ; Riedel, Ralf (2018)
SiC/HfyTa1−yCxN1−x/C ceramic nanocomposites with HfyTa1−yCxN1−x-carbon core–shell nanostructure and the influence of the carbon-shell thickness on electrical properties.
In: Journal of Materials Chemistry C, 6 (4)
doi: 10.1039/c7tc05023b
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Dense monolithic SiC/HfyTa1−yCxN1−x/C (y = 0, 0.2 and 0.7) ceramic nanocomposites were prepared upon spark plasma sintering of amorphous SiHfTaC(N) ceramic powders which were synthesized from single-source-precursors. The microstructural evolution of the ceramic powders was investigated using elemental analysis, X-ray diffraction, Raman spectroscopy and transmission electron microscopy (TEM). The results reveal that the powdered and dense monoliths of SiC/HfyTa1−yCxN1−x/C ceramic nanocomposites annealed at T ≥ 1700 °C and at 2200 °C, respectively, are characterized by the presence of a homogeneous dispersion of HfyTa1−yCxN1−x-carbon core–shell nanoparticles within a β-SiC matrix. Hf/Ta atomic ratios (or y values) of the in situ generated HfyTa1−yCxN1−x-carbon core–shell nanoparticles can be controlled precisely by molecular tailoring of the preceramic precursors, which further tunes the thickness of the in situ formed carbon shell. Interestingly, with increasing the value y the thickness of the carbon shell increases, while the electrical conductivity of the dense monolithic SiC/HfyTa1−yCxN1−x/C (y = 0, 0.2 and 0.7) nanocomposites significantly reduces. The unique HfyTa1−yCxN1−x-carbon core–shell nanostructure opens a new strategy towards tailoring the electrical conductivity of SiC/HfyTa1−yCxN1−x/C nanocomposites for potential electromagnetic applications in harsh environments.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Wen, Qingbo ; Yu, Zhaoju ; Xu, Yeping ; Lu, Yan ; Fasel, Claudia ; Morita, Koji ; Guillon, Olivier ; Buntkowsky, Gerd ; Ionescu, Emanuel ; Riedel, Ralf |
| Art des Eintrags: | Bibliographie |
| Titel: | SiC/HfyTa1−yCxN1−x/C ceramic nanocomposites with HfyTa1−yCxN1−x-carbon core–shell nanostructure and the influence of the carbon-shell thickness on electrical properties |
| Sprache: | Englisch |
| Publikationsjahr: | 2018 |
| Verlag: | Royal Society of Chemistry Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Materials Chemistry C |
| Jahrgang/Volume einer Zeitschrift: | 6 |
| (Heft-)Nummer: | 4 |
| DOI: | 10.1039/c7tc05023b |
| URL / URN: | https://doi.org/10.1039/c7tc05023b |
| Kurzbeschreibung (Abstract): | Dense monolithic SiC/HfyTa1−yCxN1−x/C (y = 0, 0.2 and 0.7) ceramic nanocomposites were prepared upon spark plasma sintering of amorphous SiHfTaC(N) ceramic powders which were synthesized from single-source-precursors. The microstructural evolution of the ceramic powders was investigated using elemental analysis, X-ray diffraction, Raman spectroscopy and transmission electron microscopy (TEM). The results reveal that the powdered and dense monoliths of SiC/HfyTa1−yCxN1−x/C ceramic nanocomposites annealed at T ≥ 1700 °C and at 2200 °C, respectively, are characterized by the presence of a homogeneous dispersion of HfyTa1−yCxN1−x-carbon core–shell nanoparticles within a β-SiC matrix. Hf/Ta atomic ratios (or y values) of the in situ generated HfyTa1−yCxN1−x-carbon core–shell nanoparticles can be controlled precisely by molecular tailoring of the preceramic precursors, which further tunes the thickness of the in situ formed carbon shell. Interestingly, with increasing the value y the thickness of the carbon shell increases, while the electrical conductivity of the dense monolithic SiC/HfyTa1−yCxN1−x/C (y = 0, 0.2 and 0.7) nanocomposites significantly reduces. The unique HfyTa1−yCxN1−x-carbon core–shell nanostructure opens a new strategy towards tailoring the electrical conductivity of SiC/HfyTa1−yCxN1−x/C nanocomposites for potential electromagnetic applications in harsh environments. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 13 Apr 2018 11:50 |
| Letzte Änderung: | 29 Okt 2018 06:39 |
| PPN: | |
| Sponsoren: | Qingbo Wen acknowledges the China Scholarship Council (CSC) for financial support (No. 201206130059)., Zhaoju Yu thanks the Natural Science Foundation of Fujian Province of China (No. 2015J01221), the Creative Research Foundation of Science, (No. 6142911040114) and the Alexander von Humboldt Foundation for financial support. |
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