A new Na0.5Bi0.5TiO3 based lead-free piezoelectric system with calculated end-member Bi(Zn0.5Zr0.5)O3

This study shows a new lead-free piezoelectric system (1−x)Na0.5Bi0.5TiO3–xBi(Zn0.5Zr0.5)O3 [(1−x)NBT–xBZZ, x=0, 0.02, 0.03, 0.035, 0.04 and 0.05]. The structure of Bi(Zn0.5Zr0.5)O3 was calculated with first-principles method. A morphotropic phase boundary (MPB) near x=0.03 between rhombohedral and pseudo-cubic phases was found, and its improvement in electrical properties was demonstrated. In the MPB composition, the maximum polarization, remnant polarization, coercive field and piezoelectric coefficient are 46.4 μC/cm2, 39.2 μC/cm2, 4.8 kV/mm and 95 pC/N, respectively. The results not only show a new lead-free piezoelectric system but also suggest a new route to designing lead-free piezoelectric materials.