Oxide ion conductivity in the hexagonal perovskite derivative Ba3MoNbO8.5
Abstract
Oxide ion conductors are important materials with a range of technological applications and are currently used as electrolytes for solid oxide fuel cells and solid oxide electrolyzer cells. Here we report the crystal structure and electrical properties of the hexagonal perovskite derivative Ba3MoNbO8.5. Ba3MoNbO8.5 crystallizes in a hybrid of the 9R hexagonal perovskite and palmierite structures. This is a new and so far unique crystal structure that contains a disordered distribution of (Mo/Nb)O6 octahedra and (Mo/Nb)O4 tetrahedra. Ba3MoNbO8.5 shows a wide stability range and exhibits predominantly oxide ion conduction over a pO2 range from 10-20 to 1 atm with a bulk conductivity of 2.2 × 10-3 S cm-1 at 600 °C. The high level of conductivity in a new structure family suggests that further study of hexagonal perovskite derivatives containing mixed tetrahedral and octahedral geometry could open up new horizons in the design of oxygen conducting electrolytes.
Citation
Fop , S , Skakle , J M S , McLaughlin , A C , Connor , P A , Irvine , J T S , Smith , R I & Wildman , E J 2016 , ' Oxide ion conductivity in the hexagonal perovskite derivative Ba 3 MoNbO 8.5 ' , Journal of the American Chemical Society , vol. 138 , no. 51 , pp. 16764-16769 . https://doi.org/10.1021/jacs.6b10730
Publication
Journal of the American Chemical Society
Status
Peer reviewed
ISSN
0002-7863Type
Journal article
Description
This research was supported by the Northern Research Partnership and the University of Aberdeen.Collections
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