authors |
Pinho, R; Tkach, A; Zlotnik, S; Costa, ME; Noudem, J; Reaney, IM; Vilarinho, PM |
nationality |
International |
journal |
APPLIED MATERIALS TODAY |
author keywords |
Potassium sodium niobate; KNN; Spark plasma sintering; Spark plasma texturing; Lead free piezoelectrics |
keywords |
FREE PIEZOELECTRIC CERAMICS; SINGLE-CRYSTALS; CA3CO4O9; FIELD |
abstract |
Controlling the sintering and microstructure of lead-free potassium sodium niobate ((K1-xNax)NbO3, KNN) ceramics is of primary importance to optimize its piezoelectric / ferroelectric properties. However, sintering dense and monophasic KNN remains a challenge. Here, we prepare KNN ceramics using spark plasma texturing (SPT), a modified spark plasma sintering (SPS) technique, in which uniaxial pressure is applied in an edge-free configuration, allowing ceramics to deform in the radial direction. Densification at low temperatures (1000 degrees C) and for short times (20 min) is achieved by SPT accompanied by constrained grain growth (average grain size =1.4 mu m), resulting in enhanced piezoelectric properties (d(33) =108 pC N-1 and g(33) = 21.2 x 10(-3) Vm N-1). In addition, and of relevance, SPT KNN ceramics reveal a more homogeneous electrical microstructure postulated to be related with a reduced diffusion and local segregation of defects, resulting in grain cores and shells with more similar capacitances and conductivities. Our work brings new practical understanding to sintering of KNN and demonstrates the potential of alternative densification strategies for improved lead-free dielectrics. (C) 2020 Elsevier Ltd. All rights reserved. |
publisher |
ELSEVIER |
issn |
2352-9407 |
year published |
2020 |
volume |
19 |
digital object identifier (doi) |
10.1016/j.apmt.2020.100566 |
web of science category |
Materials Science, Multidisciplinary |
subject category |
Materials Science |
unique article identifier |
WOS:000548712700004
|
ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
8.352 |
5 year journal impact factor |
8.383 |
category normalized journal impact factor percentile |
89.331 |
dimensions (citation analysis):
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altmetrics (social interaction):
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