Preparation and properties of Bi_4-xLa_xTi₃O₁₂ thin films

Bi_4-xLa_xTi₃O₁₂ (BLT, x=0, 0.25, 0.5, 0.75) powders were synthesized by UV radiation Sol-Gel method, and then BLT ferroelectric films doped with La³⁺ were prepared on Pt(111)/Ti/SiO₂/Si substrate. The BLT powders and films were characterized by such analysis techniques as XRD, AFM and ferroelectric test instrument. In addition, effects of crystalline temperatures on the phases of the BTO powders were studied. XRD results indicated that an amorphous phase was formed at 400°C, a pure perovskite phases Bi₄Ti₃O₁₂ was formed at 600°C. In addition, perovskite BLT(Bi_4-xLa_xTi₃O₁₂, x=0.25, 5, 0.75) powders were obtained at 500°C after BLT gel was irradiated by UV-light. A dense uniform and (020) oriented BLT(Bi_4-xLa_xTi₃O₁₂, x=0, 0.25, 0.5, 0.75) thin film was achieved, with UV-light irradiation treating the Bi-Ti Sol-Gel, and then heated at 300°C for 10 min, finally crystallized at 500°C at a rapid rising temperature.