Composition and poling condition-induced electrical behavior of (Ba_(0.85)Ca_(0.15))(Ti_(1-x)Zr_x)O_3 lead-free piezoelectric ceramics

摘要

Lead-free (Ba_(0.85)Ca_(0.15))(Ti_(1-x)Zr_x)O_3 (BCTZ) piezoelectric ceramics were fabricated by normal sintering in air atmosphere. BCTZ ceramics with x=0.10 possess a coexistence of tetragonal and rhombohedral phases at ~40 °C. The Curie temperature of BCTZ ceramics decreases with increasing the Zr content. Piezoelectric properties of BCTZ ceramics are dependent on the poling conditions (i.e., the poling temperature and the poling electric field), and the underlying physical mechanism is illuminated by the phase angle. The BCTZ (x=0.10} ceramic, which locates at the existence of two phases and is poled at E ~ 4.0 kV/mm and T_p ~ 40 °C, exhibits an optimum electrical behavior at a room temperature of ~20 °C: d_(33) ~ 423 pC/N, k_p ~ 51.2%, 2P_r ~ 18.86 μC/cm~2, 2E_c ~ 0.47 kV/mm, ε_r ~ 2892, and tan δ ~ 1.53%.