Issue 13, 2018

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 <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.

Graphical abstract: Defect chemistry and electrical properties of sodium bismuth titanate perovskite

Article information

Article type
Review Article
Submitted
20 Oct 2017
Accepted
23 Nov 2017
First published
28 Nov 2017
This article is Open Access
Creative Commons BY license

J. Mater. Chem. A, 2018,6, 5243-5254

Defect chemistry and electrical properties of sodium bismuth titanate perovskite

F. Yang, M. Li, L. Li, P. Wu, E. Pradal-Velázquez and D. C. Sinclair, J. Mater. Chem. A, 2018, 6, 5243 DOI: 10.1039/C7TA09245H

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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