Dielectric Properties of the Lead-Free Compositions Based on Sodium–Bismuth Titanate and Alkali Metal Niobates

The use of mechanical activation in the production of (1 – x)(Na0.5K0.5)NbO3–x(Na0.5Bi0.5)TiO3 ceramics is shown to increase the relative density of the ceramics by more than 10%. Several morphotropic phase transitions are found to appear in the system (1 – x)Na0.5K0.5NbO3—xBi0.5Na0.5TiO3 at room temperature. An increase in the amount of Bi0.5Na0.5TiO3 in the system under study is shown to increase the temperature stability of the dielectric properties in the range 100–250°C. Solid solutions in the system (1 – x)Na0.5K0.5NbO3–xBi0.5Na0.5TiO3 with a high Bi0.5Na0.5TiO3 content are promising bases for charge storage devices.