Structures and properties of (1-x)Bi₄Ti₃O_12-xBaTiO₃ piezoelectric ceramics with high Curie temperature

The (1-x)Bi₄Ti₃O_12-xBaTiO₃ (BIT-BT) piezoelectric ceramics with high Curie temperature were synthesized by the conventional solid state reaction. The effect of BaTiO₃ content on the microstructure and electrical properties was investigated. The results revealed that the main phases of BIT-BT were BiTi₃O₁₂ and BaTiO₃. When the molar fraction of BT was 0.1≤x≤0.7, the BaBi₄Ti₄O₁₅ phase was coexisted in the BIT-BT ceramics. With BaTiO₃ content increase, the Curie temperature T_C decreased, while the dielectric constant ε_r increased gradually. The dielectric loss tanδ and the piezoelectric constant d₃₃ increased firstly and then decreased with BaTiO₃ content increase. When the component was from 0.6BIT to 0.4BT, the ceramics had the optimal properties, its T_C was 455 °C, ε_r was 147, tan δ was 0.011 and d₃₃ was 20 pC/N.