Roncal-Herrero, T orcid.org/0000-0002-3673-6904, Harrington, J orcid.org/0000-0003-1403-4423, Zeb, A orcid.org/0000-0001-5966-8441 et al. (2 more authors) (2018) Nanoscale compositional segregation and suppression of polar coupling in a relaxor ferroelectric. Acta Materialia, 158. pp. 422-429. ISSN 1359-6454
Abstract
A number of relaxor ferroelectric ceramics have been demonstrated to possess a near stable value of relative permittivity over very wide temperature ranges. This cannot be explained by conventional theories of relaxors. One such system is based on the perovskite solid solution series: (1-x) (Ba₀.₈Ca₀.₂)TiO₃-xBi(Mg₀.₅Ti₀.₅)O₃, giving stable relative permittivity from 150 to 500 °C. We show by scanning transmission electron microscopy and electron energy loss spectroscopic elemental mapping that nanoscale compositional segregation occurs in the temperature stable relaxor composition (x = 0.55), with Ba/Ti clusters some 2–4 nm in extent, separated by Bi-rich regions of comparable size. This nanomosaic structure is consistent with phase separation into a ferroelectrically active BaTiO₃ – type phase (Ba/Ti rich) and a weakly polar Bi/(Mg) rich perovskite solid solution. The possibility that nanophase segregation is the cause of weak dipole coupling and suppression of the dielectric relaxation peak is considered.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2018 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Functional ceramics; Ferroelectric relaxor; Chemical segregation; Electron microscopy |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Funding Information: | Funder Grant number EPSRC EP/P015514/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 22 Aug 2018 11:02 |
Last Modified: | 17 Dec 2024 11:21 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.actamat.2018.07.053 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134846 |