Defect chemistry and electrical properties of sodium bismuth titanate perovskite

Abstract

The ferroelectric perovskite Na0.5Bi0.5TiO3, NBT, can exhibit three types of electrical behaviour, i.e. oxide-ion conduction (type I), mixed ionic–electronic conduction (type II) and insulating/dielectric (type III) based on various defect mechanisms. Here we review how to tune the electrical properties of NBT via several mechanisms, including A-site Na or Bi non-stoichiometry, isovalent substitution, and acceptor- and donor-doping. The diversity of the electrical behaviour in the NBT lattice is attributed to the high level of oxide-ion conductivity originating from highly mobile oxygen ions which can be fine-tuned to optimise or suppress ionic conduction. High oxide-ion conductivity can be obtained by manipulating the starting Na/Bi ≥1 and by acceptor-doping to make NBT a potential electrolyte material for intermediate temperature solid oxide fuel cells (IT-SOFCs). In contrast, the oxide-ion conduction can be partially or fully suppressed by having a starting (nominal) composition with Na/Bi less than 1, donor-doping, or utilising the trapping effect between oxygen vacancies and some B-site acceptor dopants. This significantly reduces the dielectric loss and makes NBT-based materials excellent candidates as high-temperature dielectrics for capacitor applications.

Citation

Yang, F., Li, M., Li, L., Wu, P., Pradal-Velázquez, E., & Sinclair, D. C. (2018). Defect chemistry and electrical properties of sodium bismuth titanate perovskite. Journal of Materials Chemistry A, 6(13), 5243-5254. https://doi.org/10.1039/c7ta09245h

• Journal Article Type: Article
• Acceptance Date: Nov 23, 2017
• Online Publication Date: Nov 28, 2017
• Publication Date: Mar 27, 2018
• Deposit Date: Dec 23, 2018
• Publicly Available Date: Jan 7, 2019
• Journal: Journal of Materials Chemistry A
• Print ISSN: 2050-7488
• Electronic ISSN: 2050-7496
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 13
• Pages: 5243-5254
• DOI: https://doi.org/10.1039/c7ta09245h
• Public URL: https://nottingham-repository.worktribe.com/output/1438491
• Publisher URL: https://pubs.rsc.org/en/Content/ArticleLanding/2018/TA/C7TA09245H#!divAbstract