Polymorphic Phase Transition and Domain Configurations of (K, Na)NbO 3 -Based Lead-Free Ceramics Modified by (Ba 0.6 Ca 0.4 )ZrO 3

• Published in: ECS journal of solid state science and technology 2021-01, Vol.10 (1), p.13006
• Main Authors: Xi, Kaibiao, Li, Yuanliang, Zheng, Zhanshen, Zhang, Lifang, Liu, Yun, Mi, Yueshan
• Format: Article
• Language: English
• ISSN: 2162-8769; 2162-8777
• DOI: 10.1149/2162-8777/abddda

In this work, (1−x)(K 0.5 Na 0.5 )(Nb 0.96 Sb 0.04 )−x(Ba 0.6 Ca 0.4 )ZrO 3 lead-free piezoelectric ceramics were prepared by a conventional solid-state sintering method. The relationship between the composition, structure and performance of the system was analyzed specifically. A polymorphic phase transition with rhombohedral-tetragonal (R-T) was formed in the sample with x = 0.3 at the room temperature (∼27 °C), which was tested by X-ray diffraction (XRD) and the temperature-dependent dielectric behavior. The high-density polar nanodomain regions were observed through Transmission Electron Microscope (TEM) in the sample with x = 0.3. Thanks to the rotation of the domain and the movement of the domain wall, the piezoelectric performance was improved, the ceramics with x = 0.3 possess enhanced piezoelectric properties of d 33 ∼ 325 pC/N together with a high Curie temperature of T c ∼ 335 °C. Furthermore, the thermal stability in the sample with x = 0.3 can be enhanced to (Δ d 33 /Δ d 33(25 °C) ∼ 12.54%), exhibiting good temperature stability, which guarantees the ceramics could be used in a wide temperature rage.