Improved Piezoelectric Performance in CBN‐Based Ceramic by A‐Site Doping

CaBi 2 Nb 2 O 9 (CBN) is a promising layered perovskite piezoelectric ceramic with high Curie temperature ( T C ) for vibration sensor applications. However, its relatively low resistivity and piezoelectric response limit its application in high‐temperature environments. In this work, A‐site doped Ca 0.6 (Na 0.5 Bi 0.5 ) 0.4‐ x (Li 0.5 Nd 0.5 ) x Bi 2 Nb 2 O 9 (CBN‐NBN‐ x LiNd) ceramics were synthesized using a conventional solid‐state method. The piezoelectric and electrical properties of CBN‐NBN‐ x LiNd ceramics simultaneously improved. Notably, the CBN‐NBN‐0.12LiNd ceramic exhibited excellent overall performance, including a high T C value of 904°C, an enhanced piezoelectric constant ( d 33 ∼16.5 pC/N), and excellent high‐temperature resistivity (1.37 × 10 6 Ω·cm at 600°C). Nanoindentation and Vickers hardness tests were performed to evaluate the effect of doping on the mechanical properties of CBN‐NBN‐ x LiNd ceramics, revealing a hardness of 3.56 GPa for CBN‐NBN‐0.12LiNd. These findings provide valuable insights into the development of CBN‐based ceramics for high‐temperature piezoelectric applications.