Effects of SrZrO3 addition on piezoelectric properties of Bi0.5(Na0.8K0.2)0.5TiO3 ceramic

(1 − x)Bi0.5(Na0.8K0.2)0.5TiO3–xSrZrO3 [(1 − x)BNKT–xSZ] ceramics were synthesized by conventional solid-state reaction methods, and their ferroelectric and piezoelectric properties were investigated in this study. The X-ray powder diffraction profiles of the ceramics showed a single phase in the composition range of 0–0.07; the formation of morphotropic phase boundary between rhombohedral and tetragonal phases was suggested at compositions lower than x = 0.01. From the temperature dependence of dielectric properties, both the depolarization temperature and transition temperature from a rhombohedral phase to a tetragonal phase decreased, depending on the composition x. A pinched polarization–electric field (P–E) hysteresis loop was obtained for x = 0.005, suggesting the coexistence of ferroelectric and antiferroelectric phases. The remanent polarization and coercive field of the ceramics decreased with increasing composition x, whereas d33 improved from 116 to 191 pC/N in the composition range of 0–0.005.