Preparation and Characterization of KNN-based Ceramics with High Energy Ball Milling

0.94K_0.5Na_0.5NbO₃-0.06Ba (Mg_1/3Nb_2/3)O₃ (0.94KNN-0.06BMN) ceramics were prepared by using high energy ball milling method. Particle sizes of the slurries prepared by using high energy ball milling and traditional ball milling were studied, while calcination temperature of the high energy ball milled powders was optimized. Furthermore, phase structure, microstructure, dielectric properties and ferroelectric properties of the 0.94KNN-0.06BMN ceramics were studied. The high energy ball milling method not only greatly shortened the preparation time, but also refined initial particles of the powders and grains of the final ceramics, thus leading to great changes in dielectric and ferroelectric properties. For example, dielectric constant of the ceramics prepared by using the high energy ball milling method was about 470 at 1 kHz. The remanent polarization intensity was about 20.9 μC·cm^-2 and the coercive electric field was about 19.7 kV·cm^-1.