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http://hdl.handle.net/10773/20779
Title: | Effects of transition metal additives on redox stability and high-temperature electrical conductivity of (Fe,Mg)(3)O-4 spinels |
Author: | Ferreira, N. M. Kovalevsky, A. V. Naumovich, E. N. Yaremchenko, A. A. Zakharchuk, K. V. Costa, F. M. Frade, J. R. |
Keywords: | THERMODYNAMIC PROPERTIES CATION DISTRIBUTIONS CRYSTAL-STRUCTURES POINT-DEFECTS FE-2+ IONS OXIDES SIMULATION MAGNETITE DIFFRACTION THERMOPOWER |
Issue Date: | 2014 |
Publisher: | ELSEVIER SCI LTD |
Abstract: | Magnetite-based spinels are considered as promising oxide materials to meet the requirements for ceramic consumable anodes in molten oxide pyroelectrolysis process, a breakthrough low-CO2 steel technology aimed to overcome the environmental impact of classical extractive metallurgy. The present work focuses on- the assessment of phase relationships, redox stability and electrical conductivity of Fe2.6Me0.2Mg0.2O4 (M = Ni, Cr, Al, Mn, Ti) spinel-type materials at 300-1773 K and p(O-2) from 10(-5) to 0.21 atm. The oxidation state of substituting transition metal cation, affecting the fraction of Fe2+ in spinel lattice, was found to be a key factor, which determines the electronic transport and tolerance against oxidative decomposition, while the impact of preferred coordination of additives on these properties was less pronounced. At T > 650 K thermal expansion of Fe2.6Me0.2Mg0.2O4 ceramics exhibited complex behaviour, and, in highly oxidizing conditions, resulted in significant volume changes, unfavourable for high-temperature electrochemical applications. (C) 2014 Elsevier Ltd. All rights reserved. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/20779 |
DOI: | 10.1016/j.jeurceramsoc.2014.02.016 |
ISSN: | 0955-2219 |
Publisher Version: | 10.1016/j.jeurceramsoc.2014.02.016 |
Appears in Collections: | CICECO - Artigos |
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Effects of transition metal additives on redox stability and high-temperature electrical conductivity of (FeMg)3O4 spinels_10.1016j.jeurceramsoc.2014.02.016.pdf | 1.93 MB | Adobe PDF |
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