FEATURES OF THE STRUCTURE FORMATION AND FERROELECTRIC PROPERTIES OF LEAD-FREE CERAMICS NEAR MORPHOTROPIC PHASE BOUNDARY (Bi0.5Na0.5)TiO3-(Bi0.5K0.5)TiO3 - BiFeO3

The aim of this research was to investigate the phase formation and physical-chemical properties of perovskite-like solid solutions in systems (1-y) [(1-x) (Na_0.5Bi_0.5)TiO₃ - x(K_0.5Bi_0.5)TiO₃] - yBiFeO₃ where x = 0.15 , y=0.0-0.6, Dy = 0.1 (NB1) and (1-y) [(1-x) (Na_0.5Bi_0.5)TiO₃ - x(K_0.5Bi_0.5)TiO₃] - yBiFeO₃ where x = 0.25, y = 0.0-0.6, Dy = 0.1 (NB2). It was revealed that the BiFeO₃ addition contributed to the increase in the unit cell volume and in the Curie temperature T_С. The region of the morphotropic phase transition is located in the composition range of 0.1 £ y £ 0.2 according to the concentration dependences of the dielectric characteristics.