The impact of co-doping Ce, W, and Mn on the microstructure and piezoelectric performance of high-temperature piezoelectric ceramics based on CaBi2Nb2O9

CaBi 2 Nb 2 O 9 (CBN) is a bismuth layered ferroelectric material with extremely high Curie temperature and low dielectric loss, which has great application potential in ultra-high temperature field. However, because of its low piezoelectric coefficient, its practical application still faces great challenges. This study successfully prepared Ca 1-x Ce x Bi 2 Nb 1.98 (W 2/3 Mn 1/3 ) 0.02 O 9 ( x  = 0–0.05) two-layer ferroelectric ceramics using direct-reaction sintering method. A pseudo tetragonal structure was successfully constructed near x  = 0.02 using the substitution method of Ce 4+ at site A, and W 6+ and Mn 4+ at site B, which altered the crystal structure of CBN based ceramics. The properties of CBN-based piezoelectric ceramics have been significantly improved by this modification. It has a higher piezoelectric constant ( d 33  = 20.6 pC/N) and Curie temperature ( T c  = 950 °C), while having a lower dielectric loss (tan δ  = 0.031 at 500 °C). In addition, CaBi 2 Nb 2 O 9 based piezoelectric ceramics also show excellent thermal stability. After annealing at 900 °C for 2 h, the d 33 value remained high at 19.2 pC/N, retaining about 93.2% of its original value. Therefore, these findings indicate that Ca 1-x Ce x Bi 2 Nb 1.98 (W 2/3 Mn 1/3 ) 0.02 O 9 is a high-temperature piezoelectric material with great potential.