柠檬酸-乙二胺四乙酸络合法合成La_(0.9)Ca_(0.1)CrO_3粉体  

Preparation of Calcium-doped Lanthanum Chromites Powders by Citric Acid-EDTA Complexometry

作　　者：李胜利[1] 朱新德[1] 孙良成[2,3] 敖青[1] 

机构地区：[1]山东大学材料科学与工程学院,山东济南250061 [2]包头稀土研究院,内蒙古包头014030 [3]稀土冶金及功能材料国家工程研究中心,内蒙古包头014030

出　　处：《稀土》2013年第3期41-44,共4页Chinese Rare Earths

基　　金：山东省自然科学基金(ZR2009FM069);山东省科技发展计划(2011GGX10202);济南市高校自主创新项目(201102048);山东大学自主创新项目(2010GN049)

摘　　要：用乙二胺四乙酸(EDTA)作为辅助络合剂与Ca2+单独络合,然后再与柠檬酸络合剂混合,解决了柠檬酸络合剂与Ca2+络合能力差的问题,实现了La3+、Cr3+、Ca2+三种离子在溶胶中的均匀稳定络合。利用红外光谱、热分析、X射线衍射、透射电镜对凝胶结构、热分解过程、粉体物相等进行了表征。结果表明,该工艺得到的干凝胶在500℃煅烧就可以转变为纯度较高的La0.9Ca0.1CrO3相,比单一柠檬酸体系的合成温度低200℃左右。另外,该体系中钙掺杂起到抑制铬酸镧中Cr元素挥发的作用。EDTA was used as assistant complexing agent to chelate with calcium ion solely, then mixed with citric acid, so the problem that citric acid chelated with calcium ion poorly was solved, and the three kinds of cation, La^3＋ , Cr^3＋ , Ca^2＋ , were chelated in the gel uniformly and stably. The structure and decomposition of the gel and the morphology of the powder were investigated by ATR, TG, DSC, XRD and TEM. The perovskite phase Lao.gCa0. 1 CrO3 was formed by decomposition of the dried gel at 500 ℃, 200 ℃ lower than citric acid gel system. Our investigation also showed that calcium doping played an active role in restraining the volatilization of chromium during the gel calcination.

关 键 词：乙二胺四乙酸 超细粉 溶胶-凝胶法 铬酸镧 

分 类 号：TB34[一般工业技术—材料科学与工程]