Processing and properties of ferroelectric Bi_4-xla _xTi₃O₁₂ ceramics

Bi_4-xLa_xTi₃O₁₂ (BLT, x=0, 0.75, 1, 2) ceramic powders were prepared with sol-gel and solid phase reaction processes, respectively. BLT powders were synthesized after decarbonization at 300°C for 1h followed by calcination at 800°C for 2h. The ceramics synthesized with cold isostatic pressing and sintering at 1150°C exhibit a perovskite-like structure. The influence of sintering parameters and La doping content on density, microstructure and dielectric properties of the BLT were discussed. With the increase of La doping content in Bi_4-xLa _xTi₃O₁₂, dielectric constant increases and dielectric loss gradually decreases. The dielectric constant and dielectric loss of Bi_4-xLa_xTi₃O₁₂ (x=2) are 132.7 and 0.012 at 100 KHz, respectively.