High temperature electronic properties of BaTiO₃ – Bi(Zn_1/2Ti_1/2)O₃ – BiInO₃ for capacitor applications

Solid solutions xBaTiO₃ – (1-x)(0.5Bi(Zn_1/2Ti_1/2)O₃ – 0.5BiInO₃), where x = 0.95–0.60, were prepared by conventional mixed oxide method. The single phase perovskite structure was obtained for the composition with x ≥ 0.75. Phase transformation from tetragonal to pseudocubic was observed from x-ray diffraction patterns when x decreased from 0.95 to 0.75. In tetragonal phase region, x ≥ 0.90, the increase of Bi(Zn_1/2Ti_1/2)O₃ – BiInO₃ content decreased the tetragonality and the temperature at which the relative permittivity is maximum (T_max). The increase in lattice parameter and T_max were observed in the pseudocubic phase region, x < 0.90. Additionally, a highly broad and diffuse phase transition was observed from the dielectric data in the pseudocubic phase region. The introduction of Ba vacancies in compositions with x = 0.80 and 0.75 also improved dielectric loss at high temperatures. The incorporation of BiInO₃ into the BaTiO₃ – Bi(Zn_1/2Ti_1/2)O₃ compound was also found to improve the temperature coefficient of the relative permittivity, with values as low as approximately −1,000 ppm/K. Overall, ternary perovskite solid solutions based on adding Bi(Zn_1/2Ti_1/2)O₃ – BiInO₃ to BaTiO₃ shows excellent potential for high temperature capacitor applications