Achieving high piezoelectric performance and enhanced high‐temperature resistivity in CaBi₂Nb₂O₉‐based textured ceramics.

CaBi2Nb2O9 (CBN) ceramics exhibit extremely high Curie temperature, but the low high‐temperature resistivity and low piezoelectric properties in ceramics limit their application in high‐temperature sensors. In this work, the effect of W6+ donor doping on dielectric, ferroelectric, piezoelectric properties, and resistivity of CBN ceramics were systemically investigated. In the 2 mol% W6+‐doped CBN ceramics (CBNW‐2), the piezoelectric constant (from 6.6 to 14.3 pC/N) and the high‐temperature resistivity (from 5.8 × 104 to 7.8 × 105 Ω·cm at 600°C) were significantly increased. To further improve the piezoelectric properties, we fabricated textured CBNW‐2 with a high Lotgering factor (f) of 97.1% by the templated grain growth method. The textured CBNW‐2 ceramics exhibit strong piezoelectric anisotropy. Piezoelectric constant perpendicular to the texture direction (d33⊥) increases significantly to 23 pC/N, but the piezoelectric constant parallel to the texture direction (d33∥) is only 0.9 pC/N, resulting in a large d33⊥/d33∥ of 25.6. The significant enhancement in d33⊥ can be attributed to the substantial increase in remnant polarization, which is given by the highly oriented grain arrangement. Besides, d33 after annealing at 900°C remained 21.4 pC/N and the resistivity at 600°C reached 5.7 × 105 Ω·cm. The excellent piezoelectric properties and high‐temperature resistivity of the textured CBNW‐2 ceramics indicate that it is a promising piezoelectric material for high‐temperature applications. [ABSTRACT FROM AUTHOR]