Modification of the technique and main characteristics of piezoelectric ceramics BiScO$_3$–PbTiO$_3$

A modified technique for ceramics manufacturing without forced cooling from high-temperature first stage to the low-temperature second stage is proposed. The effect of the cooling regime between two sintering stages on the piezoelectric constants was investigated.This method was used to synthesize high-temperature piezoelectric ceramics 0.36BiScO$_3$–0.64PbTiO$_3$. Structural and piezoelectric parameters of ceramics were studied. It is shown that the obtained ceramics have a tetragonal structure $(P4mm)$ and a composition close to the morphotropic phase boundary, just like the solid solution synthesized by traditional one-step technique. Ceramics synthesized by modified technique are characterized by high density, up to 97% of theoretical value. The average grain sizes of ceramics are in the range of 0.8–1.0 $\mu$m. The obtained value of the piezoelectric constant $d_{33}$ of samples synthesized by the modified technique reaches 525 pC/N.