Microstructure, Density, and Dielectric Properties of Lead‐Free (K 0.44 Na 0.52 Li 0.04 )(Nb 0.96− x Ta x Sb 0.04 )O 3 Piezoelectric Ceramics

Lead‐free (K 0.44 Na 0.52 Li 0.04 ) (Nb 0.96−x Ta x Sb 0.04 )O 3 piezoelectric ceramics were prepared by the conventional solid‐state sintering method. The grain growth of the ceramics was inhibited and the relative density was improved with Ta substituting for Nb. Increasing x led to different variations of dielectric properties before and after poling, and prevented the occurrence of orthorhombic–tetragonal phase transition (at T o − t ). All the ceramics show an intermediate relaxor‐like behavior between normal and ideal relaxor ferroelectrics. Significantly enhanced dielectric and piezoelectric properties were obtained in the ceramics with x =0.20. The ceramics are very promising lead‐free materials for electromechanical device applications.