Enhanced piezoelectricity in 0.4CaBi2Nb2O9-0.6Na0.5Bi2.5Nb2O9 through Ce/Mo co-doping

Bismuth layer-structured ferroelectrics (BLSFs) with high Curie temperature ( T C ) hold great potential for high-temperature vibration sensor applications. In this study, Ce and Mo co-doped 0.4CaBi 2 Nb 2 O 9 -0.6Na 0.5 Bi 2.5 Nb 2 O 9 BLSF ceramics with the nominal composition Ca 0.4 (Na 0.5 Bi 0.5 ) 0.6 Bi 2- x Ce x Nb 2- x Mo x O 9 (abbreviated as 0.4CBN-0.6NBN- x CeMo), were developed to achieve both favorable piezoelectric performance and high T C suitable for practical applications. The introduction of Ce/Mo co-dopants induces large lattice distortion and enhances spontaneous polarization, leading to the improved piezoelectric property (23.2 pC/N) and a high T C of 842 °C at x = 0.03. Meanwhile, this sample exhibits excellent temperature stability, maintaining piezoelectric activity up to 800 °C. In addition, the high electrical resistivity (>10 6 Ω cm at 500 °C) contributes to a low dielectric loss of 0.08 at 500 °C. These results demonstrate the strong potential of 0.4CBN-0.6NBN-0.03CeMo ceramic for high-temperature piezoelectric applications.