液相共沉淀法制备BaPbO_3导电陶瓷的研究

PREPARATION OF BaPbO_3 CONDUCTIVE CERAMIC POWDER BY LIQUID-STATE CO-PRECIPITATION METHOD

利用液相共沉淀法 ,以BaCO3和PbO为原料制备了BaPbO3陶瓷粉末。讨论了原料、焙烧温度、升温速度、保温时间对粉末性能的影响 ,并用X射线衍射及SEM对粉末的结构和形貌进行了研究。实验结果表明 :采用液相共沉淀法能明显降低BaPbO3粉末的合成温度 ,其合成温度约为 65 0℃左右 ;液相法制备的BaPbO3粉末的纯度高、粒度细 ;适当地提高升温速度可提高BaPbO3粉体的合成率和降低BaPbO3粉体的合成温度 ;液相共沉淀法制得的BaPbO3导电陶瓷的室温电阻率约为 3.4× 10 - 4 Ω·cm ,并在 75 0℃具有优良的正温度系数阻温 (PTC)

BaPbO 3conductive ceramics powder was prepared by means of liquid-state co-precipitation method (LSCM) with BaCO 3 and PbO as the raw powders. The influences of the raw materials, calcination temperature, the heating rate and the keeping time on the phase composition and morphology of prepared powder are investigated by X-ray diffraction and scanning electron microscope. The results show that the synthesizing temperature of BaPbO 3 is obviously decreased, about 650 ℃, and the purity of prepared BaPbO 3 powders is much higher and the particle size is finer by using the liquid-state co-precipitation method. The efficiency of the calcination can be increased and the formation temperature can be decreased when the heating rate is properly increased. The sintered BaPbO 3by LSCM exhibits a resistivity of 3.4× 10 -4 Ω·cm and an excellent positive temperature coefficient characteristics at Curie temperature of 750 ℃