Ceramic bismuth titanate for high – temperature electro-acoustic transducers

Abstract

Bismuth titanate Bi4Ti3O12 (BIT), which belongs to the Aurivillius family, is one of the most interesting compounds among the bismuth-based layered ceramics. BIT is a ferroelectric material with wide applications in the electronic industry, as capacitors, transducers, memory devices and sensors. BIT ceramics materials with m= 3 were prepared by conventional mixed-oxide method by solid-state reaction. Thermal and mass change effects were analyzed in air by thermogravimetric and differential thermal analysis. The crystal structure of Bi4Ti3O12 was examined at room temperature with an X-ray diffraction method using the Rietveld method. Microstructure and chemical composition were analyzed. The investigation of dielectric proprieties of Bi4Ti3O12 ceramics shows that the BIT is ferroelectric with Tc about 675○C. Due to this high transition temperature, BIT ceramics is a good material for high temperature piezoelectric applications.