Enhanced piezoelectric properties and temperature stability in KNN-based textured ceramics

Considering the advantages of high Curie temperature and environment-friendly nature of KNN piezoelectric ceramics, the limitation of weak piezoelectric response and their temperature sensitivity to applications is worth exploring. Herein, the textured (1-x)(K0.5Na0.5)(Nb0.96Sb0.04)O-3-x(Bi0.5Na0.5)HfO3(x = 0.01-0.045) lead-free ceramics were synthesized by templated grain-growth method. The high piezoelectric performance (d(33) of 474 pC/N and strain of 0.21%) and excellent temperature stability (unipolar strain maintained within 4.3% change between 30 degrees C and 165 degrees C) were simultaneously achieved in the textured KNNS-0.03BNH ceramics. The high piezoelectric performance can be attributed to the summation of the crystallographic anisotropy and phase structure contributions in textured ceramics. The superior temperature stability of piezoelectric properties can be interpreted by the contribution of crystal anisotropy to piezoelectric properties reduces the effect of phase transition on piezoelectric properties deterioration. This study provides an effective strategy for simultaneously achieving high piezoelectric properties and superior temperature stability in KNN-based textured ceramics.