Achieving outstanding comprehensive performance with high piezoelectricity in CaBi2Nb2O9-based high-temperature piezoelectric ceramics via multi-field coupling strategy

Aurivillius phase CaBi 2 Nb 2 O 9 (CBNO) ceramic with an ultrahigh Curie temperature ( T C ) of ∼934 °C shows huge potential in high-temperature piezoelectric applications. However, low piezoelectricity and poor electric insulation prevent its applications in high-temperature sensing. Here, we propose an effective multi-field coupling strategy to synergistically optimize piezoelectric property, electrical conduction behavior and temperature stability of CBNO ceramic. The constructed lattice stress and electric fields induced by introducing Li/Pr and Bi/Sc doping have great impacts on the lattice structure, microstructure, domain structure and defect chemistry. Therefore, a significant increase in piezoelectric activity ( d 33 ) is resulted from the enhancement of polarization, the improvement of breakdown electric field and the production of nanoscale domains. In especial, the existence of pseudo-tetragonal phase boundary is helpful for the enhanced d 33 . In the designed Ca 1–3 x (Li 0.5 Pr 0.5 ) x Bi 2+2 x Nb 2– x Sc x O 9 system, a high d 33 of ∼18.2 pC/N accompanied by an ultrahigh T C of ∼938 °C is achieved in the x = 0.02 ceramic. This combined with high electrical resistivity ( ρ ∼1.72 MΩ⋅cm at 600 °C) and nearly stable d 33 (up to 800 °C) indicates that it is a very promising piezoelectric material for high-temperature (up to 600 °C or higher) sensing applications. • Lattice fields induced by Li/Pr and Bi/Sc doping have great impacts on structure and electrical properties of CBNO. • Outstanding comprehensive performance with high T C ∼934 °C and d 33 ∼18.2 pC/N is realized in CBNO- x LP- x BS. • The x =0.02 ceramic is a very promising material for high-temperature (≥600 °C) piezoelectric applications. • This paper provides an effective strategy to design cutting-edge high-temperature piezoelectric ceramics.