MnO2 doping induced structural tuning drives superior piezoelectric response in CaBi4Ti4O15-based ceramics

Benefiting the fast expansion of aircraft, geological exploration, and nuclear power generation, there is a largely need for piezoelectric materials capable of performing at high temperature. CBT-based ceramics are considered one of the most promising candidates for high-temperature applications among bismuth layer-structured ferroelectrics (BLSFs) due to their exceptional T_C and piezoelectric properties. However, pure CBT ceramics exhibit poor piezoelectric performance due to the high strain energy in the pseudo-perovskite blocks between the bismuth layers limits spontaneous polarization (P_s), causing pure CBT ceramics exhibits only low d₃₃ of 8 pC/N. Consequently, substantial endeavors are required to optimize the piezoelectric performance of CBT-based ceramics, with the aim of addressing the growing imperative for high-performance and high-temperature piezoelectric sensing ceramics.

Recently, a research group of high-temperature piezoelectric ceramics led by Prof. Dr. Zong-Yang Shen from Jingdezhen Ceramic University, reported the piezoelectric properties of MnO₂ doped CaBi₄Ti_3.89(W_1/2Co_1/2)_0.11O₁₅+x wt.%MnO₂ (abbreviated as CBTWC-xMn, x=0-0.25) solid solutions through structural tuning and domain engineering modulation. The CBTWC-0.1Mn ceramics achieve an ultra-high piezoelectric coefficient of 27.3 pC/N together with high Curie temperature (T_C=754.7 ^oC), low dielectric loss (tanδ=6.7%, @500 ^oC) indicating its excellent thermal stability. This work provides a feasible strategy for improving the piezoelectric properties of bismuth layer-structured ceramics, which has important prospects for the application of high-temperature piezoelectric devices.

The team published their work in Journal of Advanced Ceramics on March 7, 2025.

“In this work, we successfully fabricated MnO₂-modified CaBi₄Ti_3.89(W_1/2Co_1/2)_0.11O₁₅ ceramics, achieved an ultra-high piezoelectric constant of 27.3 pC/N. This result is due to enhanced crystal structural distortion breaking the long-range ferroelectric order, and thus CBTWC-0.1Mn ceramics exhibit a more easily oriented domain structure as evidenced by PFM measurements.” said Prof. Zong-Yang Shen, vice dean at School of Materials Science and Engineering, Jingdezhen Ceramic University (China), whose research interests include high-temperature piezoelectric ceramics for sensor applications and dielectric ceramics for high power energy storage applications.

“The inclination (α) of the oxygen octahedron toward the c-axis and the rotation angle (∠β_O6) toward the a-b plane represent the structural distortion, as observed in the visual crystal structure. 0.1 wt% MnO₂ doping significantly affects the distortion of the octahedral layers, confirmed by the highest intensity of Raman peak and the broadened Raman half-peak width. This structural tuning of [TiO₆] plays a crucial role in boosting the piezoelectric performance.” said Zong-Yang Shen.

“Compared to CBTWC ceramics, the domains of CBTWC-0.1Mn ceramics exhibit greater uniformity and smaller size, which is primarily attributed to the disruption of long-range ferroelectric order by MnO₂ doping. For the CBTWC-0.1Mn ceramics, a lower voltage is sufficient to switch domains. Such phenomenon is due to the enhanced lattice distortion and reduction of the domain switching energy barriers. In addition, as remove the applied voltage, a large number of domains in CBTWC-0.1Mn ceramics maintain the same orientation after 10 min.” said Zong-Yang Shen.

“More importantly, CBTWC-0.1Mn ceramics obtain a maximum piezoelectric coefficient of 27.3 pC/N, and that remains 95% of the initial value at annealing temperature of 500 ^oC, owing to structural adjustments and stable domain configuration. Besides, CBTWC-0.1Mn ceramics achieve a high Curie temperature (T_C=754.7 ^oC).” said Zong-Yang Shen.

Prof. Zong-Yang Shen said “In the following work, I will work with my team to drive high-temperature piezoelectric materials to sensitive sensor application at harsh environments. We believe this work would be a great project but much more difficulty in the future. We hope find more colleagues with similar interest to join us!!!”

Other contributors include Qilai Wen, Huan-Huan Guo, Zhumei Wang, Tao Zeng, Wenqin Luo, and Fusheng Song from School of Materials Science and Engineering, Jingdezhen Ceramic University in Jingdezhen, China.

This work was supported by Key Research & Development Project of Jiangxi Province (20223BBE51018), Natural Science Foundation of Jiangxi Province (20224BAB214020), Opening Project of National Engineering Research Center for Domestic & Building Ceramics (GXZX2303), and the Graduate Innovation Fund of Jiangxi Province (JYC202309).

About Author

First Author: Qilai Wen is a third-year postgraduate studying at Jingdezhen Ceramic University. His main research interest includes piezoelectric ceramic materials.

Co-first Author: Huan-Huan Guo is currently a lecturer at School of Materials Science and Engineering, Jingdezhen Ceramic University. He obtained his PhD degree in 2020 from Xi'an Jiaotong University. His main research interest includes microwave dielectric ceramics and devices, dielectric energy storage materials, and piezoelectric ceramics.

Corresponding Author: Zong-Yang Shen is currently a professor and vice dean of School of Materials Science and Engineering, Jingdezhen Ceramic University. He obtained his PhD degree at School of Materials Science and Engineering, Wuhan University of Technology, in 2007. Afterward, he joined Prof. Jing-Feng Li’s group in Tsinghua University, as a Postdoctoral Research Fellow. In the year 2010, he joined Jingdezhen Ceramic University, and studied in MRI, Pennsylvania State University, as a visiting scholar in Prof. Shujun Zhang’s group from 2012 to 2013. His research interests include dielectric ceramics for high power density energy storage capacitors, and high Curie temperature piezoelectric ceramics. He was granted the Ninth Science and Technology Nomination Award for young scientists from the Chinese Ceramic Society in 2011 and the Polish Ceramic Society Award in 2018. He has published over 70 SCI/EI papers as the first/corresponding author.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2023 IF is 18.6, ranking in Top 1 (1/31, Q1) among all journals in “Materials Science, Ceramics” category, and its 2023 CiteScore is 21.0 (top 5%) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508