Stabilizing Effect of the Carbon Shell on Phase Transformation of the Nanocrystalline Alumina Particles Full article
| Journal |
Ceramics International
ISSN: 0272-8842 |
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| Output data | Year: 2018, Volume: 44, Number: 5, Pages: 4801-4806 Pages count : 6 DOI: 10.1016/j.ceramint.2017.12.066 | ||||||
| Tags | Alumina, Carbon coating, Core-shell structure, Phase transformations, Solid-state NMR, Stabilization effect | ||||||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Russian Science Foundation | 16-13-10168 |
Abstract:
Intensive phase transformations of alumina are known to occur at temperatures above 1000 °C. In the present work, high temperature behaviour of pure Al2O3 and the carbon coated Al2O3@C sample with core-shell structure was comparatively studied using low-temperature nitrogen adsorption, transmission electron microscopy, powder X-ray diffraction (XRD) analysis and solid-state nuclear magnetic resonance (NMR). The solid-state NMR 27Al method has allowed us to identify and estimate the concentration of all phases appeared during the transformation of pseudoboehmite γ-Al2O3 into corundum α-Al2O3. The data obtained correlate well with the results of XRD analysis and low-temperature nitrogen adsorption. It is shown that the deposition of carbon coating with formation of core-shell Al2O3@C system stabilizes the size of oxide core and prevents the formation of corundum phase until the temperatures of 1350-1400 °C, which are close to the temperature of carbothermal reduction of alumina. The stabilization of the size of the oxide core nanoparticles was considered as a main factor preventing the formation of corundum phase at high temperatures. At the same time, the carbon coating does not affect the phase transformation of γ-Al2O3 to δ-Al2O3.
Cite:
Yakovlev I.V.
, Volodin A.M.
, Zaikovskii V.I.
, Stoyanovskii V.O.
, Lapina O.B.
, Vedyagin A.A.
Stabilizing Effect of the Carbon Shell on Phase Transformation of the Nanocrystalline Alumina Particles
Ceramics International. 2018. V.44. N5. P.4801-4806. DOI: 10.1016/j.ceramint.2017.12.066 WOS Scopus РИНЦ AN OpenAlex
Stabilizing Effect of the Carbon Shell on Phase Transformation of the Nanocrystalline Alumina Particles
Ceramics International. 2018. V.44. N5. P.4801-4806. DOI: 10.1016/j.ceramint.2017.12.066 WOS Scopus РИНЦ AN OpenAlex
Dates:
| Submitted: | Dec 2, 2017 |
| Accepted: | Dec 8, 2017 |
| Published online: | Dec 10, 2017 |
| Published print: | Apr 1, 2018 |
Identifiers:
| Web of science: | WOS:000425204400035 |
| Scopus: | 2-s2.0-85039045644 |
| Elibrary: | 35522649 |
| Chemical Abstracts: | 2017:1972750 |
| OpenAlex: | W2774069611 |