Effect of Ba_(0.85)Ca_(0.15)Ti_(0.90)Zr_(0.10)O_3 content on the microstructure and electrical properties of Bi_(0.51)(Na_(0.82)K_(0.18))_(0.50)TiO_3 ceramics

摘要

(1-x)Bi_(0.51)(Na_(0.82)K_(0.18))_(0.50)TiO_3-xBa_(0.85)Ca_(0.15)Ti_(0.90)Zr_(0.10)O_3 [(1-x)BNKT-xBCTZ] ceramics were prepared by the conventional solid-state method, and the effect of BCTZ content on their microstructure and electrical properties was investigated. A stable solid solution with a pure perovskite phase is formed between BNKT and BCTZ, and these ceramics have a coexistence of rhombohedral and tetragonal phases in the range of 0 ≤ x < 0.15. Their T_m and T_d values are strongly independent on the BCTZ content. Moreover, the sintering temperature strongly affects the ferroelectric and piezoelectric properties of these ceramics with x = 0.02. These ceramics with x = 0.02 exhibit an optimum electrical behavior of d_(33) ~ 205, k_p ~ 0.25, P_r ~ 31.8 ìC/cm~(-2), and E_c ~ 19.1 kV/cm together with a high T_d value of ~91 °C when sintered at 1180 °C and poled at an optimum condition. As a result, the (1-x)BNKT-xBCTZ ceramic is a promising candidate material for lead-free piezoelectric ceramics.