Crystal Structure and Electrical Properties of Lead‐Free (1 − x)BaTiO3–x(Bi1/2A1/2)TiO3 (A = Ag,Li, Na,K, Rb,Cs) Ceramics

Ceramics of solid solutions (1  ?  x)BaTiO₃–x(Bi_1/2A_1/2)TiO₃ (A = Ag, Li, Na, K, Rb, Cs, x ≤ 0.20) were prepared and their crystal structures, dielectric, ferroelectric, and piezoelectric properties were investigated. It was found that (Bi_1/2A_1/2)TiO₃‐type doping compounds broadened the temperature range of the tetragonal phase in BaTiO₃ and all the compositions examined displayed a tetragonal structure at room temperature. The Curie temperature (T_C) was observed to increase with respect to pure BaTiO₃ to the range 140°C–210°C through solid solution. Remanent polarization (P_r) tended to decrease with increased content of doping compound, whereas the coercive field (E_C) rose and piezoelectric coefficient (d₃₃) fell. The highest d₃₃ value in the solid solutions was observed in 0.97BaTiO₃–0.03(Bi_1/2Ag_1/2)TiO₃ at 90 pC/N.