Effect of Alkali Elements Content on the Structure and Electrical Properties of (K0.48Na0.48Li0.04)(Nb0.90Ta0.04Sb0.06)O3 Lead-Free Piezoelectric Ceramics

In this communication, we report on the effects of alkaline elements (K, Na, and Li) content on the electrical properties of (K0.48Na0.48Li0.04)(Nb0.90Sb0.06Ta0.04)O3 ceramics. Because of the high volatility, the alkaline elements evaporate during the high‐temperature sintering process, generating vacancy defects in the ceramics. As a result, the ferroelectric and piezoelectric properties of the ceramics become weakened. Our results reveal that the volatilization loss can be effectively compensated by a 1 mol% excess of alkaline elements. The remanent polarization Pr, piezoelectric coefficient d33, and electromechanical coupling coefficient kp of the compensated ceramics are improved by 15%, 16%, and 20%, respectively, having a value of 30 μC/cm2, 310 pC/N, and 0.6.