Surta, T.W. orcid.org/0000-0002-2882-6483, Keeney, L. orcid.org/0000-0003-0980-514X, Manjón-Sanz, A.M. et al. (7 more authors) (Cover date: 15 February 2024) Separation of K+ and Bi3+ displacements in a Pb-free, monoclinic piezoelectric at the morphotropic phase boundary. Acta Materialia, 265. 119594. ISSN 1359-6454
Abstract
The best piezoelectric properties of any perovskite oxide known are found in the solid solution of the relaxor Pb(Mg1/3Nb2/3)O3 and ferroelectric PbTiO3. Despite its impressive properties, this system has limited analogy. We present the compositional exploration of the Pb-free analogue (1-x)(K1/2Bi1/2)(Mg1/3Nb2/3)O3-x(K1/2Bi1/2)TiO3 (KBMN-KBT). We locate the morphotropic phase boundary between x = 0.86 and 0.88 changing from Cm to Pm symmetry and the optimally performing composition at x = 0.88. We report a piezoelectric figure of merit (d33*) of 192 pm V−1 from strain measurements. Diffraction methods reveal disordered displacements of K+ and Bi3+ which persist from the KBMN endmember through multiple changes in symmetry. Rearrangement of the Bi3+ displacements along the uncommon [011]c direction drives the physical response. Ferroelectric, dielectric, and piezoresponse force microscopy are used to study the progression of physical properties through the MPB and attribute the mechanism to a polarization rotation. Taking account for local, short-range, and average structural features yield a balanced perspective on the structure and properties of this system, isolating the driving force within this system to the Bi3+ bonding configuration. This work yields a strong analogy to the Pb-based analogue, and provides strategies for further optimization.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2023 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: | Perovskite oxide, Relaxor, Piezoelectric, Ferroelectric, Structural analysis |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Jan 2024 16:57 |
Last Modified: | 12 Jan 2024 16:57 |
Published Version: | http://dx.doi.org/10.1016/j.actamat.2023.119594 |
Status: | Published |
Publisher: | Elsevier BV |
Identification Number: | 10.1016/j.actamat.2023.119594 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:207048 |