Enhanced piezoelectric properties of (Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_3 lead-free ceramics by optimizing calcination and sintering temperature

摘要

Lead-free (Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_3 (BCTZ) piezoelectric ceramics were prepared by conventional oxide-mixed method at various calcination and sintering temperatures. Both calcination and sintering temperatures have a significant effect on the density and grain size, which are closely related with piezoelectric and other properties of ceramics. The calcination temperature has a great influence on the grain boundary, which also plays an important role in piezoelectric properties. With increased calcination and sintering temperature, the ferroelectric and piezoelectric properties have enhanced significantly. The BCTZ ceramics calcined at 1300 °C and sintered at 1540 °C exhibit optimal electrical properties: d_(33) = 650 pC/N, d_(31) = 74 pC/N, k_p = 0.53, k_t = 0.38, k_(31) = 0.309, s_(11)~E = 14.0 x 10~(-12) m~2/N, ε_r=4500, P_r = 11.69 μC/cm~2, which is a promising lead-free piezoelectric candidate.