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Thermotropic Phase Boundaries in Classic Ferroelectrics
Nature Communications
  • Tom T. A. Lummen
  • Yijia Gu, Missouri University of Science and Technology
  • Jianjun Wang

High-performance piezoelectrics are lead-based solid solutions that exhibit a so-called morphotropic phase boundary, which separates two competing phases as a function of chemical composition; as a consequence, an intermediate low-symmetry phase with a strong piezoelectric effect arises. In search for environmentally sustainable lead-free alternatives that exhibit analogous characteristics, we use a network of competing domains to create similar conditions across thermal inter-ferroelectric transitions in simple, lead-free ferroelectrics such as BaTiO3 and KNbO3. Here we report the experimental observation of thermotropic phase boundaries in these classic ferroelectrics, through direct imaging of low-symmetry intermediate phases that exhibit large enhancements in the existing nonlinear optical and piezoelectric property coefficients. Furthermore, the symmetry lowering in these phases allows for new property coefficients that exceed all the existing coefficients in both parent phases. Discovering the thermotropic nature of thermal phase transitions in simple ferroelectrics thus presents unique opportunities for the design of 'green' high-performance materials.

Materials Science and Engineering
Keywords and Phrases
  • chemical composition,
  • lead,
  • nonlinearity,
  • performance assessment,
  • piezoelectricity, article,
  • electric field,
  • electrical parameters,
  • electricity,
  • experimental study,
  • ferroelectrics,
  • fluorescence imaging,
  • phase transition,
  • piezoelectricity
Document Type
Article - Journal
Document Version
Final Version
File Type
© 2014 Nature Research, All rights reserved.
Creative Commons Licensing
Creative Commons Attribution 4.0
Publication Date
Citation Information
Tom T. A. Lummen, Yijia Gu and Jianjun Wang. "Thermotropic Phase Boundaries in Classic Ferroelectrics" Nature Communications Vol. 5 (2014) ISSN: 2041-1723
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