Microstructure, crystalline phase, and electrical properties of ZnO-added Li0.06(Na0.535K0.48)0.94NbO3 ceramics

ZnO-doped Li0.06(Na0.535K0.48)0.94NbO3 ceramics were synthesized by a conventional mixed-oxide method. A dense microstructure was achieved and was free from deliquescence when ZnO was added. With adding 0.6 mol% ZnO, the Zn2+ first enters the A-site, while higher amounts of Zn2+ substitutes B-site ions. The addition of ZnO changes the ceramics to ‘‘hard’’ performance with improvement of Qm to 235. A phase transition from tetragonal to orthorhombic phase was obtained in the compositional range of 0.6–0.8 mol% ZnO. Because of such transitional behavior, d33, kp, and εr reached peak values of 250 pC/N, 45%, and 986, respectively.