Preparation and Properties of Fine‐Grain (1− <i>x</i> )BiScO ₃ − <i>x</i> PbTiO ₃ Ceramics by Two‐Step Sintering

Abstract

(1− x )BiScO 3 − x PbTiO 3 (BSPT) nanopowder with an average grain size of 10 nm with the composition of x =0.64, which has been reported to be close to the MPB in the bulk BSPT ceramics, was successfully synthesized. Subsequently, the techniques of preparation of high‐performance fine‐grain MPB–BSPT ceramics by two‐step sintering were investigated, providing a feasible approach to produce a high‐density fine‐grain MPB–BSPT ceramic using pressureless means without any sintering aids at a low temperature of 800°C. The results have shown that the fine‐grain ceramic possesses a higher piezoelectric constant and electromechanical coupling factor than the coarse‐grain ceramic. The influences of the grain size on the piezoelectric and dielectric properties were also discussed. Within the scale of the grain sizes of our specimens, the piezoelectric constant increases up to 520 pC/N at the finest grain size of 200 nm, indicating a promising path for the improvement of the piezoelectric coefficient.