(南昌大学 化学与材料学院，南昌 330047)
摘 要: 从多酸化学的角度，讨论了在化学共沉淀法制备正铌酸镧(LaNbO4)过程中,不同pH条件对产物相组成的影响。结果表明：在酸性条件下，由于同多酸盐的析出，产物中有部分偏铌酸镧相K2LaNb5O15存在；在碱性条件下,由于铌酸盐的水解受到抑制，可以制备得到相组成相对单一的正铌酸镧相；对酸性条件下得到的无定形前驱体粉末进行碱化处理可以降低烧成正铌酸镧相中的杂相含量。
关键字: 正铌酸镧；化学共沉淀法；偏铌酸镧相
produced during process of making
LaNbO4 by coprecipitation approach
（School of Chemistry & Materials Science, Nanchang University,
Nanchang 330047, China）
Abstract:Lanthanum orthoniobate (LaNbO4) amorphous pre cursors are prepared by coprecipitation approach，using K3NbO4 and LaCl3 as the raw reagents. Fro mpolyacid chemistry, the influence of homo-polyniobate on the phase constitution of LaNbO4 is investigated. The XRD patterns reveal that the hydrolization of niobate can be restrained in an alkaline system, so pure LaNbO4 can be obtained. The DSC analysis also confirms that in an acid system, there is byproduct K2LaNb5O15 in the product due to the hydrolization of homo-polyniobate. The content of K2LaNb5O15 in acid powder can be reduced by alkaline treatment.
Key words: lanthanum orthoniobate; coprecipitation; K2L aNb5O15
