Piezoelectric behavior of (1−x)K0.50Na0.50NbO3−xBa0.80Ca0.20ZrO3 lead-free ceramics

(1−x)K_0.50Na_0.50NbO₃–xBa_0.80Ca_0.20ZrO₃ (1−x)KNN–xBCZ] lead-free ceramics were prepared by the conventional solid-state method, and the effect of BCZ content on their phase structure and piezoelectric properties was studied. A coexistence of rhombohedral–orthorhombic phases was identified in the range 0.04<x<0.08. With increasing the BCZ content, their grain size becomes smaller, and their Curie temperature gradually decreases. An optimum piezoelectric behavior of d₃₃∼197 pC/N and k_p∼40.6% was demonstrated in the ceramic with x=0.06 because of the coexistence of two phases. As a result, the introduction of BCZ could further improve piezoelectric properties of KNN ceramics.