Yang, F., Wu, P. orcid.org/0000-0001-6571-0255 and Sinclair, D.C. (2018) Electrical conductivity and conduction mechanisms in (Na0.5Bi0.5TiO3)1-x(BiScO3)x (0.00 ≤ x ≤ 0.25) solid solutions. Journal of Materials Chemistry C. ISSN 2050-7526
Abstract
The electrical properties of (Na0.5Bi0.5TiO3)1−x(BiScO3)x (NBT-BS, 0.00 ≤ x ≤ 0.25) solid solutions are established by ac impedance spectroscopy and electromotive force transport number measurements. The bulk conductivity decreases with increasing BS incorporation but the oxide-ion transport number remains high (>0.85) over a wide compositional range 0.00 ≤ x ≤ 0.15 and drops to ∼0.7 for x ≥ 0.20. NBT-BS solid solutions can only present either predominant oxide-ion conduction or mixed ionic-electronic conduction behaviour, indicating that oxide-ion conduction cannot be fully eliminated by incorporation of BS. This is in contrast from our previous study where incorporation of ∼7% BiAlO3 (BA) can fully suppress the oxide-ion conduction in NBT. The conductivity–composition relationships of NBT-BS solid solutions are attributed to a competing effect from lattice expansion, which enlarges the channel for oxygen ion migration, with trapping between B-site acceptor ions, Image ID:c8tc04679d-t1.gif, and oxygen vacancies, Image ID:c8tc04679d-t2.gif, which decreases oxygen ion migration. Comparisons between NBT-BS, NBT-BA and NBT-BiGaO3 (BG) solid solutions suggest that small acceptor ions on the B-site are more effective in trapping oxygen vacancies and consequently more effective to suppress the oxide-ion conduction and thus reduce dielectric loss at elevated temperatures.
Metadata
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Copyright, Publisher and Additional Information: | © 2018 The Royal Society of Chemistry. This is an author produced version of a paper subsequently published in Journal of Materials Chemistry C. Uploaded in accordance with the publisher's self-archiving policy. | ||||
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Institution: | The University of Sheffield | ||||
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) | ||||
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Depositing User: | Symplectic Sheffield | ||||
Date Deposited: | 19 Oct 2018 13:28 | ||||
Last Modified: | 12 Oct 2019 00:38 | ||||
Published Version: | https://doi.org/10.1039/C8TC04679D | ||||
Status: | Published online | ||||
Publisher: | Royal Society of Chemistry | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1039/C8TC04679D |