Composition induced rhombohedral-tetragonal phase boundary and high piezoelectric activity in (K0.48,Na0.52) (Nb(1-x)Sbx)O3 - 0.05Ca0.2(Bi0.5,Na0.5) 0.8ZrO3 lead-free piezoelectric ceramics

New lead-free piezoelectric ceramics (K0.48,Na0.52) (Nb(1-x)Sbx)O3 −0.05Ca0.2(Bi0.5,Na0.5) 0.8ZrO3 (KNNSx-CBNZ) were fabricated by traditional solid-state sintering process. The effects of Sb content on phase structures and electrical properties of the KNNSx-CBNZ ceramics were studied. Because Sb5+ can increase the rhombohedral-orthorhombic phase transition temperature and decrease orthorhombic-tetragonal phase transition temperature simultaneously, it is found that the ceramics in the composition range of 0.02