Phase transition and piezoelectric properties of dense (K0.48,Na0.52)0.95Li0.05SbxNb(1−x)O3-0.03Ca0.5(Bi0.5,Na0.5)0.5ZrO3 lead free ceramics

A newly designed system of (K0.48Na0.52)0.95Li0.05SbxNb(1−x)O3- 0.05Ca0.5(Bi0.5Na0.5)0.5ZrO3 (KNLSxN-CBNZ) lead-free ceramics were prepared by conventional solid state reaction method. Effects of antimony (Sb) content on their phase structure, microstructure, electrical properties and sinterability were systematically studied. It is found that ceramics with 0.06 ≤ x ≤ 0.08 possess a rhombohedral-tetragonal (R-T) phase boundary, as confirmed by the results of temperature dependence of dielectric properties and X-ray diffraction patterns. In addition, the ceramic with x = 0.06 has optimum piezoelectric properties (d33 = 267 pC/N, kp = 45.2%, εr = 1836, tan δ = 3.32%, Tc = 253 °C) with a quite high density (ρ = 4.63 g/cm3). As a result, we believe that the ceramic system is a promising lead-free piezoelectric candidate for practical applications.