水热法制备K_(0.5)Bi_(0.5)TiO_3陶瓷粉体及其介电性能研究

Hydrothermal Synthesis of K_(0.5)Bi_(0.5)TiO_3 Nanometer Powders and Studies on Dielectric Properties

采用水热法合成了K0.5Bi0.5TiO3（KBT）无铅压电陶瓷粉体。运用X线衍射（XRD）分析了KOH浓度及反应时间对产物物相的影响;利用扫描电镜（SEM）和透射电镜（TEM）观察研究了粉体的形貌。结果表明,增大碱浓度（4~12 mol/L）和延长反应时间都有利于KBT纳米粉体的合成。在220℃,KOH的起始浓度12 mol/L水热合成48 h的纯KBT相呈立方形结构,晶型规整,晶粒尺寸约为100 nm。由水热法制备的粉体在1 060℃烧结,获得介电损耗为0.05的致密压电陶瓷材料。

K0.5Bi0.5TiO3（KBT） nano-powders were fabricated by a hydrothermal method.The as-prepared KBT powders were characterized by X-ray powder diffraction（XRD）,infrared（IR） spectroscopy,scanning electron microscope（SEM）,and transmission electron microscope（TEM）.The effects of KOH concentration and reaction time were investigated.The results showed that increasing KOH concentration（4~12 mol/L） or extending reaction time would in favor of the formation KBT nanometer powders.Under the reaction condition with temperature of 220 ℃,and with KOH concentration of 12 mol/L for 48 hours,the TEM observation revealed that KBT nano-powders possessed a feature of cubic shape and a nano-scale of about 100 nm.The KBT ceramics sintered at 1 060 ℃ from hydrothermal powders showed compact structure with a small dielectric loss of 0.05.