液相合成铌酸钾粉体的研究  

Study of Potassium Niobate Powders by Liquid Phase Synthesis

作　　者：苗鸿雁[1] 王世平[1] 谈国强[1] 

机构地区：[1]陕西科技大学材料科学与工程学院,陕西咸阳712081

出　　处：《稀有金属材料与工程》2007年第A01期7-9,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目(50372039)和(50672055);陕西省教育厅专项科研计划项目(05JK152)

摘　　要：以Nb2O5、K2CO3、HF和(NH4)2C2O4为原料,以柠檬酸为配位剂,乙二醇为酯化剂,用氨水调节溶液的pH值,首先将Nb2O5在水浴条件下溶于HF,加入(NH4)2C2O4和氨水获得沉淀物,而后用柠檬酸溶解获得Nb-柠檬酸溶液。K2CO3与Nb-柠檬酸溶液在乙二醇的交联作用下形成了K-Nb凝胶前驱体。用XRD和SEM研究了不同pH值、不同柠檬酸与金属离子的摩尔比条件下所形成的凝胶前驱体在不同温度下煅烧所得粉体的相组成和形貌。研究发现当柠檬酸与金属离子的摩尔比为3:1,柠檬酸和乙二醇的摩尔比为1:2时,可形成稳定的K-Nb前驱体溶液和凝胶。分析结果表明,K-Nb凝胶前驱体在加热过程中分解成K2CO3相,K2CO3与Nb-柠檬酸溶液发生反应生成KNbO3凝胶,凝胶经800℃煅烧3h或160℃水热反应8h可以制备出颗粒分布均匀的纯钙钛矿型KNbO3粉体。IR谱表明,800℃煅烧或160℃水热反应都出现了Nb-O的特征峰。Potassium niobate were prepared with niobium pentoxide, potassium carbonate, hydrofluoric acid and ammonium acetate as source material. Citric acid and ethylene glycol acted as assistant agent. The effects of pH value, the different ratio of Citric acid to Nb ion and the different ratio of Citric acid to ethylene glycol on phase structure and microstructure morphology of KNbO3 powders have been investigated by XRD and SEM. The results showed that K-Nb precursor gel was formed at pH value between 7-8, the ratio of Citric acid to Nb ion is 3：1 and the ratio of Citric acid to ethylene glycol is 1：2. Pure perovskite KNbO3 powders can be obtained at 800 ℃ calcinations for 3 h or at 160 ℃ hydrothermal processing for 8 h .The results of IR showed that the character peak of Nb-O can be detected by both methods.

关 键 词：液相法 铌酸钾 凝胶前驱体 

分 类 号：O614[理学—无机化学]