摘要
以钐和铁的硝酸盐为起始物,用EDTA络合溶胶-凝胶法制备SmFeO3/Fe2O3复合纳米永磁性粉体,并对工艺参数进行了优化。用TG-DTA、SEM、XRD等手段对制备过程、热分解机理及粉体的性质进行了研究。结果表明:采用分段升温焙烧方式可以明显改变晶化过程;采用无水乙醇对凝胶洗涤、加入合适的分散剂及采用超声波分散都可以在一定程度上减少团聚的产生;同时硝酸根离子在高温条件下可以加速EDTA凝胶的热分解,仅在350℃就有SmFeO3相生成,但此温度下有Sm2O2CO3相出现,需经600℃焙烧2h才能彻底除去。粉体颗粒呈球形,分散性较好,经谢乐公式计算,平均粒径在30nm左右。与传统固相反应相比,该法制得的组分均一,化学计量比易于控制,焙烧温度较低,是一种制备复合钠米材料的有效方法。
Using nitrates and ethylene diamine tetra acetic acid （EDTA） as raw materials, nanometer sized SmFeO3 powder was prepared by using sol-gel method, the parameters of process were optimized. XRD, SEM and TG-DTA were used to characterize the material and its formation process theory. The results show that crystallization process can be changed by temperature-gradient method to waste precursors;washing dry-gel with ethanol and ultrasonic dispersing all can deduce agglomerated particles . Nitration can accelerate the decomposition of the gel, and the SmFeO3 phase has been formed as 350℃ ,but Sm2O2CO3 occurs at this temperature. The calcinations temperature higher than 600 ℃ is needed to get rid of it completely and obtain the fine powder of mono phase SmFeO3. The particle of the powders are uniform, spherical, disperse with the average size about 30nm in diameter. This technique gives a better compositional homogeneity and a decreased calcinations temperature as compared with conventional solid state reaction. EDTA can bind with most metal elements of the periodic table , making this technique a versatile tool in the production of new nanometer materials of complex oxides.
出处
《信息记录材料》
2006年第1期50-54,共5页
Information Recording Materials
基金
大连市计划项目(20021302)
