High piezoelectric coefficient and temperature stability of Ga_2O_3-doped (Ba_(0.99)Ca_(0.01))(Zr_(0.02)Ti_(0.98))O_3 lead-free ceramics by low-temperature sintering

摘要

Lead-free ceramics with compositions of Ga_2O_3-doped (Ba_(0.99)Ca_(0.01)XZr_(0.02)Ti_(0.98))O_3 (BCZT-xGa) were fabricated by the conventional solid-state method. The effect of Ga_2O_3 addition on phase structure, micro-structure, dielectric and piezoelectric properties of BCZT-xGa ceramics was investigated. The grain size was strongly affected by Ga_2O_3 addition, and the solid solutions show a single phase perovskite structure. With the addition of small amount of Ga_2O_3, Curie temperature (T_c) maintained at about 120 °C. The ceramics with x = 0.08 sintered at 1350 °C exhibit enhanced electrical properties of d_(33) ~440 pC/N, k_p ~ 56%, P_r ~ 15.3 μC/cm~2, and E_c ~ 0.15 kV/mm, and greatly improved temperature stability of the piezoelectric properties were obtained in the temperature range from 30 to 115 °C.