Chen, H., Jiang, C., Wong, V.-K., Lim, D. B. K., Yin, J., Tan, Z., Yao, K., & Zhu, J. (2026). High-entropy design for improved CBTa-based piezoelectric ceramics and high-temperature ultrasonic applications. Acta Materialia, 305, 121870. https://doi.org/10.1016/j.actamat.2025.121870
Abstract:
Aurivillius-type bismuth layer-structured ferroelectric CaBi2Ta2O9 (CBTa) material has shown potential for high-temperature piezoelectric ultrasonic transducer application. However, practical implementation is limited by the relatively low piezoelectric coefficient, high sintering temperature, and a lack of ultrasonic experimental verification. In this work, we introduce an A/B-site substituted CBTa system based on a high-entropy strategy and significantly enhance the piezoelectric constant d33 from 5.4 pC/N in pure CBTa ceramic to 12.1 pC/N in Ca0.74Li0.03Na0.1Ce0.04Bi2.09Ta1.4Nb0.2W0.2Ti0.2O9 (CLNCBTaNWT-2) ceramic, attributed to the enhanced ferroelectricity with the effective incorporation of the substituting ions into the CBTa lattice. The sintering temperature is significantly reduced from 1200 °C to 900 °C due to the reduction in the energy barrier for grain boundary diffusion. In addition, our ultrasonic experiments demonstrate that the symmetric zero-order mode (S0) and antisymmetric zero-order mode (A) ultrasonic wave modes generated by obtained CLNCBTaNWT-2 ceramic remained high signal-to-noise ratios of 12.2 dB and 19.7 dB, respectively, up to 400 °C. These results demonstrate that the CBTa-based ceramic system designed with high-entropy strategy is promising for high-temperature ultrasonic structural health monitoring (SHM) applications.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the A*STAR - Industry Alignment Fund – Industry Collaboration Projects Grant
Grant Reference no. : I2301E0027