Effect of oxide dopants on the structure and electrical properties of (Na0.5K0.5)NbO3-LiSbO3 lead-free piezoelectric ceramics

The alkaline niobate-based perovskite ceramics (K,Na,Li)(Nb,Sb)O3 has been regarded as a new candidate of lead-free piezoelectric materials due to its excellent piezoelectric properties. In this study, 0.948(Na0.5K0.5)NbO3-0.052LiSbO3 (KNN-LS) based ceramics were prepared by a conventional solid-state reaction method. The effects of ZnO, CuO and MnO2 on the structure, dielectric and piezoelectric properties of KNN-LS were investigated in this study. When 1 mol% oxide dopants were added, respectively, KNN-LS piezoelectric ceramics became “hard”. Mechanical quality factor Q value increased significantly with unobvious change of d33 (93-119 pC/N). KNN-LS ceramics kept high Curie temperature Tc around 350 °C. Dielectric loss at 1 KHz decreased a lot to below 5%. The results show that the oxide-doped KNN-LS ceramics are promising lead-free piezoelectric materials for electromechanical transducer applications.