Interstitial oxide ion conductivity in the layered tetrahedral network melilite structure

Kuang, X. and Green, M.A. and Niu, H. and Zajdel, P. and Dickinson, C. and Claridge, J.B. and Jantsky, L. and Rosseinsky, M.J. (2008) Interstitial oxide ion conductivity in the layered tetrahedral network melilite structure. Nature Materials, 7 (6). pp. 498-504. ISSN 1476-1122. (doi:https://doi.org/10.1038/nmat2201) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1038/nmat2201

Abstract

High-conductivity oxide ion electrolytes are needed to reduce the operating temperature of solid-oxide fuel cells. Oxide mobility in solids is associated with defects. Although anion vacancies are the charge carriers in most cases, excess (interstitial) oxide anions give high conductivities in isolated polyhedral anion structures such as the apatites. The development of new families of interstitial oxide conductors with less restrictive structural constraints requires an understanding of the mechanisms enabling both incorporation and mobility of the excess oxide. Here, we show how the two-dimensionally connected tetrahedral gallium oxide network in the melilite structure La1.54 Sr0.46 Ga3 O7.27 stabilizes oxygen interstitials by local relaxation around them, affording an oxide ion conductivity of 0.02-0.1Scm1 over the 600-900°C temperature range. Polyhedral frameworks with central elements exhibiting variable coordination number can have the flexibility needed to accommodate mobile interstitial oxide ions if non-bridging oxides are present to favour cooperative network distortions. © 2008 Nature Publishing Group.

Item Type: Article
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Nat. Mater. [Field not mapped to EPrints] AD - Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, United Kingdom [Field not mapped to EPrints] AD - NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States [Field not mapped to EPrints] AD - Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115, United States [Field not mapped to EPrints] AD - Department of Chemistry, University College London, 20 Gordon Street, London W1X 0AJ, United Kingdom [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Charge carriers, Electrolytes, Gallium compounds, Solid oxide fuel cells (SOFC), Vacancies, Interstitial oxide conductors, Isolated polyhedral anion structures, Melilite structure, Oxide mobility, Oxygen interstitials, Ionic conductivity
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Giles Tarver
Date Deposited: 15 Oct 2015 11:03 UTC
Last Modified: 16 Oct 2015 11:02 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/51015 (The current URI for this page, for reference purposes)
  • Depositors only (login required):