Pairing High Piezoelectric Coefficients, d(33), with High Curie Temperature (T-C) in Lead-Free (K,Na)NbO3
authors Rafiq, MA; Costa, ME; Vilarinho, PM
nationality International
journal ACS APPLIED MATERIALS & INTERFACES
author keywords lead-free; piezoelectrics; ferroelectrics; potassium sodium niobate; template grain growth; single crystals; textured ceramics
keywords TEMPLATED GRAIN-GROWTH; TEXTURE DEVELOPMENT; SINGLE-CRYSTALS; (1-X)(NA0.5K0.5)NBO3-XLINBO(3) CERAMICS; SRBI2TA2O9 CERAMICS; MICROSTRUCTURE; STABILITY; TITANATE; BEHAVIOR; STRAIN
abstract The largest piezoelectric properties, d(33) = 416 pC/N and 490 pC/N, in KxNa1-xNbO3 ceramics have been reported for compositions close to polymorphic phase transition (PPT); however, they also have Curie temperatures, T-C, of around 217-304 degrees C, considerably lower than those of undoped KNN ceramics (420 degrees C). High d(33) along with high T-C remains the ideal choice for applications but, unfortunately, not attained up to now. Here, we show that using KNN single crystals as seeds for template grain growth (TGG) of KNN ceramics enables dramatic improvements in the electromechanical properties while maintaining a high T-C. The (001)-oriented (K0.5Na0.5)(0.98)Li0.02NbO3 ceramics engineered by TGG using (K0.5Na0.5)NbO3 crystals as templates exhibit a high d(33) of 280 pC/N while maintaining the high T-C of 430 degrees C. Enhanced piezoelectricity is attributed to long-range ordered ferroelectric domain patterns consisting of 90 degrees and 180 degrees domains, similar to single crystals. It is the first time that pairing high d(33) and high T-C in KNN, keeping a high PPT temperature, is achieved. This study is an unequivocal proof that it is possible to maximize d(33), keeping a high T-C in KNN without resorting to heavily doped compositions. This work opens the door to high-performance, rare-earth free, compositionally simple lead-free and low-cost electromechanical compounds, which can largely expand lead-free piezoelectrics applications.
publisher AMER CHEMICAL SOC
issn 1944-8244
year published 2016
volume 8
issue 49
beginning page 33755
ending page 33764
digital object identifier (doi) 10.1021/acsami.6b08199
web of science category Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
subject category Science & Technology - Other Topics; Materials Science
unique article identifier WOS:000389963300048
  ciceco authors
  impact metrics
times cited (wos core): 4
journal impact factor (jcr 2016): 7.504
5 year journal impact factor (jcr 2016): 7.823
category normalized journal impact factor percentile (jcr 2016): 89.482
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