BNT-BT粉体的低温合成及陶瓷性能研究

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

研究了0.94Bi0.5Na0.5TiO3-0.06BaTiO3[记为BNT-6BT]无铅压电陶瓷的预烧温度对陶瓷粉体相结构的影响,并在低温合成了BNT-6BT陶瓷粉体,利用这些粉体,采用传统固相烧结工艺,制备了BNT-6BT无铅压电陶瓷;研究了不同预烧温度对BNT-6BT压电陶瓷压电性能、介电和铁电性能的影响。结果表明BNT-6BT陶瓷粉体可以在600℃合成,与通常在900℃合成相比,大大降低了BNT-6BT陶瓷粉体的预烧温度;采用传统的陶瓷固相烧结工艺,利用在600℃合成的粉体所制备的压电陶瓷,其电学性能有所提高:密度ρ=5.87g/cm3,压电常数d33=141pC/N,平面机电耦合系数kp=0.30,机械品质因数Qm=141,居里温度TC=278℃,去极化温度Td=132℃,相对介电常数εr=1643,自发极化强度Pr=23μC/cm2和矫顽场Ec=32kV/cm。

The relationship between the calcined temperature and the phase structure for the 0.94Bi0.5Na0.5TiO3-0.06BaTiO3（BNT-6BT） ceramic powders was systematically studied,and the BNT-6BT ceramic powder was successfully synthesized at low temperature（600℃）.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℃,which significantly reduces the calcined temperature compared to the usually used at 900℃;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℃） exhibits excellent electrical properties with ρ=5.87g/cm3,d33=141pC/N,kp=0.30,Qm=141,TC=278℃,Td=132℃,εr=1643,Pr=23μC/cm2 and Ec=32 kV/cm.