New method for fabrication of lead-free BaTiO3 piezoelectric ceramics

BaTiO₃ (BT) powders were synthesized by hydrothermal method for fabricating lead-free barium titanate piezoelectric ceramics. The effect of the two washing methods (distilled water and acetic acid solutions) on the piezoelectric properties of the BT ceramics was studied. BT ceramics with the higher piezoelectric properties (d₃₃ value is over 190 pC/N) was obtained from the powders washed by acetic acid solution. The BaTiO₃ ceramics from three types (BT01, BT03 and BT05) of hydrothermally synthesized BaTiO₃ powders were sintered using traditional sintering method and microwave sintering method separately. Their piezoelectric properties were investigated and compared. The results indicate that only the specimens sintered by traditional sintering method from BT03 powders have better structure and higher piezoelectric properties (d₃₃ value about 350 pC/N), all the specimens sintered by the microwave method exhibit high d₃₃ value (over 350 pC/N). Our work shows that hydrothermal method and microwave sintering is very useful to enhance the piezoelectric properties of BT ceramics.