Enhanced energy-storage performance and temperature-stable dielectric properties of (1-x)[(Na0.5Bi0.5)0.95Ba0.05]0.98La0.02TiO3-xK0.5Na0.5NbO3 lead-free ceramics

Polycrystalline (1-x)[(Na0.5Bi0.5)(0.95)Ba-0.05](0.98)La0.02TiO3-xK(0.5)NbO(3) systems were prepared using the solid-state reaction technique. Modification of (Na0.5Bi0.5)(0.95)Ba-0.05](0.98)La0.02TiO3 ceramic with a proper amount of K(0.5)Na(0.5)NbO(3)can effectively improve the temperature-stable of dielectric properties. A variation in dielectric constant is maintained smaller than +/- 5% from 80 to 300 degrees C accompanied with a low dielectric loss (<= 0.04). The relaxor properties of the doped samples are significantly enhanced. A high energy storage density of 1.1 J/cm(3) and efficiency similar to 80% at 90 kV/cm are achieved in the x = 0.05 composition. Hence, the as-prepared ceramics might be practical in dielectric constant which can work stably at a high temperature range and pulsed capacitors.