Cabral, M, Brown, AP orcid.org/0000-0001-9692-2154, Bultitude, J et al. (9 more authors) (2023) Structural investigation of the temperature-stable relaxor dielectric Ba0.8Ca0.2TiO3-Bi(Mg0.5Ti0.5)O3. Journal of the European Ceramic Society, 43 (2). pp. 362-369. ISSN 0955-2219
Abstract
Aberration corrected scanning transmission electron microscopy (STEM) and electron diffraction have been used to disclose local structure and nano-chemistry in a Ca modified BaTiO3-Bi(Mg0.5Ti0.5)O3 relaxor dielectric ceramic which exhibits high and near-invariant relative permittivity over a wide temperature range. High-resolution, synchrotron X-ray diffraction indicated a globally cubic structure (Pm3m), but direct atomic-scale imaging by STEM revealed local tetragonal distortions. Nanopolar clusters were identified from B-site atomic displacement vectors measured relative to oxygen ion positions along < 100 > and < 110 > zone axes of integrated differential phase contrast (iDPC) STEM images, highlighting cluster sizes of 2–5 nm. Chemical analysis by STEM-energy dispersive X-ray spectroscopy and full pattern refinements of X-ray powder diffraction data each implied high levels of Bi vacancies within the matrix. The possibility that these A-site vacancies modulate the nanopolar structure and promote flattening of the permittivity-temperature response in this class of dielectric is discussed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Microstructure; Nanostructure; Structure-Property Relationships; dielectrics; X-ray; diffraction |
Dates: |
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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 (Engineering and Physical Sciences Research Council) EP/P015514/1 EPSRC (Engineering and Physical Sciences Research Council) EP/V028855/1 EPSRC (Engineering and Physical Sciences Research Council) EP/M028143/1 EPSRC (Engineering and Physical Sciences Research Council) EP/J021156/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Oct 2022 16:02 |
Last Modified: | 25 Jun 2023 23:06 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jeurceramsoc.2022.09.039 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:191444 |