Preparation and Characterization of (K0.5Na0.5)0.94-2xLi0.06SrxNb0.98Sb0.02O3 Lead-free Piezoelectric Ceramics

Lead-free (K0.5Na0.5)0.94-2xLi0.06SrxNb0.98Sb0.02O3 (KNLSN-Srx; x=0-0.03) piezoelectric ceramics were prepared by conventional solid-state sintering process. The sintering characteristic, the microstructure, dielectric, piezoelectric and ferroelectric properties of KNLSN-Srx ceramics were investigated. XRD results show that all samples exhibite a pure perovskite phase with tetragonal symmetry, indicating that the Sr2+ has diffused into the KNLSN lattices to form a solid solution. The grain size of KNLSN-Srx ceramics was increased with the increasing of Sr-doping level. The proper sintering temperature of KNLSN-Srx ceramics shifted to higher temperature with increasing the content of Sb. Higher d33 and kp, lower tanδ and Qm were obtained as Li, Sr and Sb were added into KNN ceramics. The comprehensive good properties of doped (K0.5Na0.5)NbO3 ceramics were obtained when Sr content was 2mol% (d33=130pC/N, kp=34.5%, tanδ=4.2%).