Atomic-resolution electron microscopy of nanoscale local structure in lead-based relaxor ferroelectrics
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iDPC_PMNV2.pdf
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Accepted version
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10.99 MB
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Author(s)
Kumar, Abinash
Lebeau, James M
Date Issued
September 2020
Journal
Nature Materials
Publisher
Springer Science and Business Media LLC
Citation
Kumar, Abinash et al. “Atomic-resolution electron microscopy of nanoscale local structure in lead-based relaxor ferroelectrics.” Nature Materials, 12 (September 2020): 3876 © 2020 The Author(s)
Version
Author's final manuscript
Abstract
Relaxor ferroelectrics, which can exhibit exceptional electromechanical coupling, are some of the most important functional materials, with applications ranging from ultrasound imaging to actuators. Since their discovery, their complex nanoscale chemical and structural heterogeneity has made the origins of their electromechanical properties extremely difficult to understand. Here, we employ aberration-corrected scanning transmission electron microscopy to quantify various types of nanoscale heterogeneities and their connection to local polarization in the prototypical relaxor ferroelectric system Pb(Mg1/3Nb2/3)O3–PbTiO3. We identify three main contributions that each depend on Ti content: chemical order, oxygen octahedral tilt and oxygen octahedral distortion. These heterogeneities are found to be spatially correlated with low-angle polar domain walls, indicating their role in disrupting long-range polarization and leading to nanoscale domain formation and the relaxor response. We further locate nanoscale regions of monoclinic-like distortion that correlate directly with Ti content and electromechanical performance. Through this approach, the connections between chemical heterogeneity, structural heterogeneity and local polarization are revealed, validating models that are needed to develop the next generation of relaxor ferroelectrics.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1038/s41563-020-0794-5
