Processing and dielectric properties of Bi_4Sr_(n-3)Ti_nO_(3n+3) (n = 3, 4 and 5) ceramics obtained from mechanochemically activated precursors

摘要

The processing of ceramics of ferroelectric, high-Curie temperature Bi_4Ti_3O_(12),Bi_4SrTi_4O_(15) and Bi_4Sr_2Ti_5O_(18) from nanometer particle size powders, obtained by mechanochemical activation, is studied for piezoelectric applications. The effect of the size of the perovskite block (n value) on the density, texture and microstructure of the ceramics processed from the mechanoactivated powders is established. Dielectric properties as a function of temperature and frequency, and piezoelectric coefficients are measured. These powders allow Aurivillius single phase ceramics with good properties to be processed at temperatures significantly lower than conventional solid state reactions.