水热法合成(K,Na)NbO_3陶瓷粉体及其压电性能研究

HYDROTHERMAL SYNTHESIS OF(K,Na)NbO_3 POWDERS AND STUDY ON PIEZOELECTRIC PROPERTIES

利用水热法在碱性溶液中合成了具有钙钛矿结构的(K,Na)NbO_3无铅压电陶瓷粉体,研究了初始溶液中K+的含量对产物晶相、形貌以及化学组成的影响。采用X射线衍射仪以及扫描电镜对产物的结构和形貌进行了表征,利用X荧光分析仪对粉体的化学组成进行了精确分析。实验结果表明:随着初始溶液中K^+含量的变化,有两相钙钛矿(K,Na)NbO_3粉体生成,在溶液中K^+的反应活性低于Na^+。然后,将水热合成的K_(0.58)Na_(0.42)NbO_3粉体采用传统固相烧结制备陶瓷材料,其结构较致密,压电常数d_(33)达到94 pC/N。

（K,Na）NbO_3 powers with perovskite structure were successfully prepared by hydrothermal method in alkaine solution.The influence of the molar ratio of K~＋on the structure,morphology and chemical composition of the products were investigated.The phase of the powers was investigated by X-ray diffraction （XRD）,the microstructure and morphology were investigated by SEM,the chemical composition of the products was investigated by XRF.The results show that with the change of the K~＋in the starting solutio,two-phase perovskite（K,Na）NbO_ appeared,the reactivity of K~＋was less than that of Na~＋in the solution.Then,the obtained K_（0.58）Na_（0.42）NbO_3 powders were used to fabricate lead-free piezoelectric ceramics using the traditional sintering process,and its piezoelectric constant up to d_（33）=94pC/N