Processing and dielectric properties of Bi0.5Na0.5TiO3 ceramics

Piezoelectric materials have an important role in electronic industry for devices such as sensors, actuators, motors and transducers, due to ability of converting between mechanical and electrical energies. Lead-based... [ view full abstract ]

Piezoelectric materials have an important role in electronic industry for devices such as sensors, actuators, motors and transducers, due to ability of converting between mechanical and electrical energies. Lead-based materials, such as PZT, are mostly used materials for this purpose, due to excellent piezoelectric properties. However, high toxicity of lead causes an enormous research effort to replace it with different lead-free materials. Bismuth sodium titanate has been recognized as a good candidate as it shows good ferroelectric and piezoelectric properties.

Bismuth sodium titanate (Bi_0.5Na_0.5TiO₃) powder was prepared by sol-gel method in acidic environment. Sodium acetate (CH₃COONa), bismuth nitrate (BiNO₃·5H₂O) and titanium butoxide (C₁₆H₃₆O₄Ti) were mixed and stirred at 70 °C at for different time. The obtained gel was dried at 200 °C and subsequently calcinated at 700 °C for 2 hours. Prepared powders were pressed into pellets and sintered at different temperatures up to 1100 °C in order to obtain dense ceramics. One of the aims in this work was to investigate influence of processing parameters on phase composition and sinterability of the prepared ceramics. Characterization of material was done by X-ray analysis, Raman spectroscopy, scanning electron microscopy and dielectric measurement.