Publication details for Prof. Ivana EvansTate, M. L., Fuller, C. A., Avdeev, M., Brand, H. E. A., McIntyre, G. J. & Radosavljevic Evans, I. (2017). Synthesis and characterisation of new Bi(iii)-containing apatite-type oxide ion conductors: the influence of lone pairs. Dalton Transactions 46(37): 12494-12499.
- Publication type: Journal Article
- ISSN/ISBN: 1477-9226 (print), 1477-9234 (electronic)
- DOI: 10.1039/C7DT02871G
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
Lone-pair cations are known to enhance oxide ion conductivity in fluorite- and Aurivillius-type materials. Among the apatite-type phases, the opposite trend is found for the more widely studied silicate oxide ion conductors, which exhibit a dramatic decrease in conductivity on Bi(III) incorporation. In this work, the influence of lone-pair cations on the properties of apatite-type germanate oxide ion conductors has been investigated by preparing and characterising seven related compositions with varying Bi(III) content, by X-ray and neutron powder diffraction and impedance spectroscopy. All materials are very good oxide ion conductors (with conductivities of up to 1.29 × 10−2 S cm−1 at 775 °C). Increasing Bi(III) content leads to increases in conductivity by up to an order of magnitude, suggesting significant differences in the oxide-ion conduction mechanisms between lone-pair-containing apatite-type germanate and silicate solid electrolytes.