Surface Morphology and Composition of a NbC/C Composite Studied by Scanning Electron Microscopy and X-Ray Photoelectron Spectroscopy

Autor: A. Yu. Teterin, Yu. A. Teterin, E. G. Il’in, A. S. Parshakov, Konstantin I. Maslakov
Rok vydání: 2020
Předmět:
Zdroj: Inorganic Materials. 56:443-450
ISSN: 1608-3172
0020-1685
DOI: 10.1134/s0020168520050052
Popis: The surface morphology and composition of a NbC/C composite prepared via thermal decomposition of the products of reaction between NbCl5 and acetylene [9] have been studied by scanning electron microscopy and X-ray photoelectron spectroscopy. The results demonstrate that the NbC thus synthesized consists of nanocrystals. The surface layer of the NbC/C composite contains nine carbon atoms per Nb atom. The niobium is present in the form of the NbC carbide (33%) and the NbO2 (10%) and Nb2O5 (57%) oxides, with Nb 3d5/2 electron binding energies of 203.8, 205.0, and 207.2 eV, which are tentatively attributed to Nb2+ (NbC), Nb4+, and Nb5+ ions, respectively. The presence of NbO2 and Nb2O5 in the surface layer is due to active reaction of the NbC/C composite with atmospheric oxygen and moisture during the sample preparation process. Our results on the structure of the C1s electron spectra lead us to assume that the carbon on the surface of the composite particles has the form of a graphene-like carbon material. The composite does not become charged when exposed to an X-ray beam, which suggests that it is a weak dielectric.
Databáze: OpenAIRE
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