Enhancement of the piezoelectric properties of CaBi2Nb2O9 ceramics through co-doping with K/Ce and In/W

Calcium bismuth niobate (CBNO), known for its high Curie temperature ( T C ), has been investigated as a potential material for vibration sensor due to its ability to operate at elevated temperatures. However, the inherent weakness in piezoelectric response of CBNO has limited its sensing performance. This study successfully induced pseudo-tetragonal distortion in CBNO through the co-doping effects of K/Ce at A site and In/W at B site. This modification altered the interaction between the perovskite layer and the bismuth layer, thereby enhancing both piezoelectric and ferroelectric properties. The co-doped Ca 0.94 (K 0.5 Ce 0.5 ) 0.06 Bi 2 Nb 1.96 (In 1/3 W 2/3 ) 0.04 O 9 exhibits a significantly enhanced piezoelectric coefficient ( d 33 ) of 22.3 pC/N, compared to the 5~7 pC/N for pure CBNO ceramics, and the remanent polarization ( P r ) increased to 11.91 μC/cm 2 , compared to 3.83 μC/cm 2 for CBNO. Furthermore, the sample maintains a suitable resistivity ( ρ = 2.46 × 10 5 Ω·cm) even at 600°C. This work not only deepens the understanding of bismuth layer structure ferroelectrics (BLSFs) but also proposes a viable co-doping strategy, providing an effective approach for developing high-performance, high-temperature-resistant piezoelectric sensors.