(南昌大學(xué) 化學(xué)與材料學(xué)院，南昌 330047)
摘 要: 從多酸化學(xué)的角度，討論了在化學(xué)共沉淀法制備正鈮酸鑭(LaNbO4)過(guò)程中,不同pH條件對(duì)產(chǎn)物相組成的影響。結(jié)果表明：在酸性條件下，由于同多酸鹽的析出，產(chǎn)物中有部分偏鈮酸鑭相K2LaNb5O15存在；在堿性條件下,由于鈮酸鹽的水解受到抑制，可以制備得到相組成相對(duì)單一的正鈮酸鑭相；對(duì)酸性條件下得到的無(wú)定形前驅(qū)體粉末進(jìn)行堿化處理可以降低燒成正鈮酸鑭相中的雜相含量。
關(guān)鍵字: 正鈮酸鑭；化學(xué)共沉淀法；偏鈮酸鑭相
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
