Enhancement of the temperature stabilities in yttrium doped (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 ceramics

Lead-free (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 + x mol% (x = 0–0.8) Yttrium ceramics (BCZT-Y) were prepared using the solid-state reaction technique. High piezoelectric coefficient of d33 = 360 pC/N and planar electromechanical coupling factor of kp = 42% were obtained at x = 0.2. Furthermore, greatly enhanced temperature stabilities of the piezoelectric properties were obtained in the temperature range from 20 to 100 °C, in which the BCZT-Y ceramics exhibited pure tetragonal phase. With the increase of Yttrium content, the orthorhombic–tetragonal phase transition shifted toward low temperature, while Curie temperature (TC) maintained at about 120 °C. The results indicate that the BCZT-Y ceramics are promising lead-free materials for practical applications.

► Enhanced temperature stability was obtained in the range from 20 and 100 °C.
► TO–T shifted toward low temperature and Tc maintained 120 °C with the increase of Y.
► High d33 = 360 pC/N and kp = 42% were obtained for the sample of BCZT-Y2.