Dielectric and piezoelectric properties of (1 − x)(K0.498Na0.498Li0.04)NbO3–x(Bi0.5Na0.5)0.9Ba0.1(Zr0.0055Ti0.9945)O3 lead-free ceramics

(1 − x)(K0.498Na0.498Li0.04)NbO3–x(Bi0.5Na0.5)0.9Ba0.1(Zr0.0055Ti0.9945)O3 (KNLN–BNBZT100x, x = 0, 0.01, 0.02, 0.03, 0.05, 0.1) lead-free ceramics were prepared by conventional solid-state reaction technique. The influences of the BNBZT on the crystal structure, dielectric, and piezoelectric properties of the ceramics were investigated. The ceramics formed single-phase solid solutions with perovskite structure after sintering in air at 1050–1100 °C for 3–4 h. Morphotropic phase boundary (MPB) between orthorhombic and tetragonal phase was found in the composition range of 0.01 ≤ x ≤ 0.02. The Curie temperature, Tc, and the orthorhombic–tetragonal transition temperature, TO–T, shifted to low temperature as BNBZT increased. The dielectric and piezoelectric properties of ceramics were enhanced for the composition near the MPB. The maximum value, 194 pC/N, of piezoelectric constant d33 together with the mechanical quality factor Qm, 20, were obtained when BNBZT content was 2 mol%.