Influence of sintering temperature on the structure and piezoelectric properties of ZnO-modified （Li, Na, K）NbO₃ lead-free ceramics

Hai-tao Li 1, 2) , Bo-ping Zhang 2) , Wei-gang Yang 2) , and Nan Ma 2) 1) School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China 2) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘 要：ZnO-modified （Li, Na, K）NbO3 lead-free ceramics with a nominal composition of Li 0.06 （Na 0.535 K 0.48 ） 0.94 NbO3 +0.7mol% ZnO （LNKN-Z 7 ） was synthesized normally at 930-1000°C. The Zn ions incorporated into the A-site at a higher sintering temperature, which changed LNKN-Z 7 to soft piezoelectric ceramics with the mechanical quality factor decreasing from 228 to 192. A phase transition from tetragonal to orthorhombic symmetry was identified by XRD analysis, and the corresponding calculation of lattice parameters was conducted at 970-980°C. Because of such transitional behavior and fine microstructure, the optimized values of piezoelectric coefficient, planar electromechanical coupling coefficient, and relative dielectric constant were obtained.

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