Investigation of the low-temperature synthesis and the properties of BNT-BT ceramics

The relationship between the calcined temperature and the phase structure for the 0.94Bi _0.5Na _0.5TiO ₃- 0.06BaTiO ₃ (BNT-6BT) ceramic powders was systematically studied, and the BNT-6BT ceramic powder was successfully synthesized at low temperature (600°C). The BNT-6BT lead-free piezoelectric ceramics made from these powders have been prepared by using traditional solid-state synthesis method, and the effect of the calcined temperature of the powders on the electrical properties for the ceramics was also studies. The results show that BNT-6BT ceramics powder can be synthesized at 600°C, which significantly reduces the calcined temperature compared to the usually used at 900°C; the electrical properties of the piezoelectric ceramics slightly increase with the decreasing of the calcined temperature; and the BNT-6BT ceramics made from the powder synthesized at low temperature (600°C) exhibits excellent electrical properties with ρ=5.87g/cm ³, d ₃₃=141pC/N, k _p=0.30, Q _m=141, T _C=278°C, T _d=132°C, ε _r=1643, P _r=23μC/cm ² and E _c=32 kV/cm.