Effects of K content on the dielectric, piezoelectric, and ferroelectric properties of 0.95(KxNa1−x)NbO3−0.05LiSbO3 lead-free ceramics

The effects of K content on the dielectric, piezoelectric, and ferroelectric properties of 0.95(KxNa1−x)NbO3−0.05LiSbO3 (0.95KxNN−0.05LS) (x=0.25–0.75) lead-free piezoelectric ceramics prepared by conventional solid-state sintering were studied. The experimental results show that the dielectric, piezoelectric, and ferroelectric properties strongly depend on K content in the 0.95KxNN−0.05LS ceramics. The 0.95KxNN−0.05LS (x=0.40) ceramics exhibit enhanced electrical properties (d33≈280 pC/N; kp≈49.4%; Tc∼364 °C; To-t=25 °C; εr≈1463; tan δ≈2.3%; Pr∼30.8 μC/cm2; Ec∼14.0 kV/cm). The enhanced electrical properties of 0.95KxNN−0.05LS (x=0.40) ceramics are attributed to the polymorphic phase transition near room temperature. These results show that 0.95KxNN−0.05LS (x=0.40) ceramic is a promising lead-free piezoelectric material.