High piezoelectric coefficient and temperature stability of Ga2O3-doped (Ba0.99Ca0.01)(Zr0.02Ti0.98)O3 lead-free ceramics by low-temperature sintering

Lead-free ceramics with compositions of Ga2O3-doped (Ba0.99Ca0.01)(Zr0.02Ti0.98)O3 (BCZT-xGa) were fabricated by the conventional solid-state method. The effect of Ga2O3 addition on phase structure, microstructure, dielectric and piezoelectric properties of BCZT-xGa ceramics was investigated. The grain size was strongly affected by Ga2O3 addition, and the solid solutions show a single phase perovskite structure. With the addition of small amount of Ga2O3, Curie temperature (Tc) maintained at about 120 °C. The ceramics with x = 0.08 sintered at 1350 °C exhibit enhanced electrical properties of d33 ∼ 440 pC/N, kp ∼ 56%, Pr ∼ 15.3 μC/cm2, and Ec ∼ 0.15 kV/mm, and greatly improved temperature stability of the piezoelectric properties were obtained in the temperature range from 30 to 115 °C.