High-temperature anion and proton conduction in RE3NbO7 (RE = La, Gd, Y, Yb, Lu) compounds. Issue 11 (October 2015)

• Record Type: Journal Article
• Authors: Chesnaud, A.; Braida, M.-D.; Estradé, S.; Peiró, F.; Tarancón, A.; Morata, A.; Dezanneau, G.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 11(2015:Nov.)
• Page Start: 3051
• Page End: 3061
• Publication Date: 2015-10
• Subjects: Protonic ceramic fuel cell -- Rare-earth niobate -- Combustion synthesis -- Fluorite-type structure -- Electrical properties; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.04.014
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The oxide-ion and proton conduction properties of RE3 NbO7 (RE = La, Gd, Y, Yb, Lu) compounds were investigated. For the bigger rare-earth cation, i.e. La 3+, the compound crystallises in a weberite-type structure and the oxide-ion conductivity is low owing to the lack of intrinsic oxygen vacancies. Consequently, the resultant proton incorporation and conductivity in La3 NbO7 are also low. For small rare-earth cations, i.e. from Gd 3+ to Lu 3+ and for RE = Y, materials adopt a fluorite-like structure confirmed from X-ray powder diffraction. In this latter case, materials include intrinsic oxygen vacancies leading to a higher oxygen conductivity. For these compounds, a proton incorporation takes place at low temperature under wet conditions giving rise to proton conductivity. Nevertheless, both oxygen and proton conductivities are low in these materials, which can be explained by the ordering of oxygen vacancies observed by Transmission Electron Microscopy.