Response of intergrown microstructure to an electric field and its consequences in the lead-free piezoelectric bismuth sodium titanate
Date
2012
Authors
Liu, Yun
Noren, Lasse
Studer, Andrew J
Withers, Raymond
Guo, Yiping
Li, Yongxiang
Yang, Hiu
Wang, Jian
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Volume Title
Publisher
Academic Press
Abstract
We investigate the R3c average structure and micro-structure of the ceramic Bi 0.5Na 0.5TiO 3 (BNT) in situ under applied electric fields using diffraction techniques. Electron diffraction implies the presence of significant octahedral tilt twin disorder, corresponding to the existence of a fine scale intergrown microstructural (IGMS) 'phase' within the R3c rhombohedral average structure matrix. A careful neutron refinement suggests not only that the off-centre displacements of the cations relative to the oxygens in the R3c regions increases systematically on application of an electric field but also that the phase fraction of the IGMS regions increases systematically. The latter change in phase fraction on application of the electric field enhances the polar displacement of the cations relative to the oxygen anions and affects the overall strain response. These IGMS regions form local polar nano regions that are not correlated with one another, resulting in polarisation relaxation and strain behaviour observed in BNT-containing materials.
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Keywords
Keywords: Applied electric field; Average structure; Bismuth sodium titanate; Diffraction techniques; In-phase; In-situ; Lead-free piezoelectrics; Micro-structural; Oxygen anion; Phase fractions; Strain response; TiO; Bismuth; Electron diffraction; Microstructure; Bismuth sodium titanate; Electron diffraction; Intergrown microstructure; Neutron diffraction
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Source
Journal of Solid State Chemistry
Type
Journal article
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2037-12-31
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