板状LiNbO_3-Li_3NbO_4复合粒子的水热合成研究

Study on hydrothermal synthesis of platelike LiNbO_3-Li_3NbO_4 composite particles

以板状K4Nb6O17为前驱体,LiOH为Li源,采用水热与热处理两步过程法合成了LiNbO3-Li3NbO4复合粒子.通过X射线衍射、场发射扫描电子显微镜、热重-差热对样品进行了表征,研究了水热反应中碱浓度与热处理温度等对LiNbO3-Li3NbO4复合粒子晶体结构和形貌的影响.实验结果表明,随着反应体系中LiOH浓度的升高,Li3NbO4样品的结晶性提高,随着热处理温度的升高,Li3NbO4与LiNbO3复合相的结晶性增强.

The composite particle of LiNbO3-Li3NbO4 is synthesized via a two-step of hydrothermal and heat treatment process,using plate-like K4Nb6O17 as precursor,LiOH as Li source.The physical properties of the as-prepared samples were characterized by X-ray diffraction（XRD）,field emission scanning electron microscope（FE-SEM）and thermogravimetry（TG）and differential thermal analysis（DTA）and the effects of the alkali concentration of hydrothermal reaction and the temperature of heat treatment on the crystal structure and morphology of the composite particle of LiNbO3-Li3NbO4 were discussed.Results show that with the rise of the alkali concentration in hydrothermal reaction,the crystallinity of the Li3NbO4 increases and the higher heat treatment temperature leads to better crystallinity of the LiNbO3-Li3NbO4 composite.