Simultaneously achieved high piezoelectricity and resistivity in CaBi2Nb2O9-based ceramics with high curie temperature

Abstract

To guarantee the functional operation of high-temperature piezoceramics in harsh circumstances, both large piezoelectricity and superior resistivity are prerequisites. However, it remains a formidable challenge to achieve these objects. Herein, we report Ce-doped CaBi2Nb2O9-based high-temperature polycrystals, which can simultaneously deliver a high piezoelectric coefficient d33 of 21.8 pC/N and decent resistivity ρ of 7.1 × 107 Ω﹒cm at 500 °C, along with a high Curie temperature of 916 °C. More encouragingly, the materials are also gifted with exceptional thermal stability ( < 10% variation of d33 in a broad range from ambient temperature up to 900 °C). In-depth multiscale structural characterizations unveil that the outstanding comprehensive performance of Ce-doped CaBi2Nb2O9-based ceramics originate from the synergistic effects of refined grain size and domain morphology, and reduced defect concentration. This work not only demonstrates that CaBi2Nb2O9-based ceramics hold enormous potential for high-temperature implements, but also offers prospects to exploit high-performance high-temperature piezoceramics.