Effect of Changing Na/K Ratio on Structure and Electrical Properties of (Na x K y ) (Nb 0.885 Sb 0.08 )–0.035LiTaO 3 Lead‐Free Piezoelectric Ceramics

(Na x K y ) (Nb 0.885 Sb 0.08 )–0.035LiTaO 3 lead‐free piezoelectric ceramics (N x K y NS–LT) with an excessive amount of Na or K were synthesized by conventional solid‐state processes. Effects of Na/K ratio on structure and electrical properties of N x K y NS–LT ceramics were investigated. Excessive Na or K did not change the major crystal structure and barely influenced the sintering temperature, but excessive Na or K exhibited effects on grain size. Better piezoelectric properties of the ceramics were achieved when a certain amount of excessive K was added (the Na/K ratio before calcining was adjusted to 0.520:0.450). X‐Ray fluorescence was used to examine the cause, and the enhanced properties are attributed to the formation of an MPB‐like composition when the Na/K was changed. Specimens with properties of d 33 =183 pC/N, k p =0.33, Q m = 103 were obtained in this work.