Structure, piezoelectric, ferroelectric and dielectric properties of lead-free ceramics 0.67BiFeO 3 –0.33BaTiO 3 – x BiGaO 3 +0.0035MnO 2

BF–BT–xBGa (shortened for 0.67BiFeO3–0.33BaTiO3–xBiGaO3+0.0035MnO2) lead-free piezoelectric were prepared by a conventional solid-state sintering method. The phase structure, miscostructure, piezoelectric, ferroelectric and dielectric properties were investigated. BiGaO3 doping has little effect on the crystal structure of BF–BT–xBGa lead-free piezoelectric ceramics. All samples are perovskite structure. With the change of x, the structure of the sample is pseudo cubic structure. The ceramics (with x = 0.02 sintered at 990 °C) has Pr = 25 µC/cm2, Ec = 22.059 kV/cm and high depolarization temperature Td = 422 °C. It was found that the piezoelectric properties of the ceramic were improved by addition of BiGaO3. The ceramic shows excellent electrical properties when x is 0.02: d33 = 170 pC/N and Tc = 434 °C. Proper amount of BiGaO3 doping can improve the size of the crystal and promote the sintering of samples. These results show that the addition of BiFeO3–BaTiO3 based ceramics is promising lead-free piezoelectric ceramics for practical applications.