Structure and electrical properties in Sb-doped Ba_(0.93)Ca_(0.07)Ti_(0.92)Sn_(0.08)O_3 ceramics near the phase coexistence point

摘要

In this work, Sb-doped Ba_(0.93)Ca_(0.07)Ti_(0.92)Sn_(0.08_O_3 ceramics were successfully prepared by conventional solid-phase sintering reaction process and their phase structure, microstructure, and electrical properties were investigated systematically. The enhanced piezoelectric and dielectric properties (d_(33) - 520 pC/N, k_p = 0.475, Q_m = 149.3, ε_r = 6113 and tanδ = 1.73%) were obtained due to the coexistence of rhombohedral, orthorhombic and tetragonal phases near the room temperature. Meanwhile, the optimal ferroelectric properties (P_r = 8.17 μC/cm~2, E_c = 1.56 kV/cm) were also gained at x = 0.15 mol%. The temperature dependence of dielectric constant reveals relaxation behavior at various frequencies, and relevant diffuse phase transition has been carefully studied. The large c/33, et, low tanδ and the relaxation behavior in (1- x)Ba_(0.93)Ca_(0.07)Ti_(0.92)Sn_(0.08)O_3-xSb_2O_3 (x = 0.15 mol%) ceramic make it as a potential candidate for high power piezoelectric applications and ceramic capacitors.