柠檬酸盐凝胶法制备γ-氧化铁纳米粒子

Preparation of nano-maghemite by citrate-gel process

纳米γ-氧化铁（γ-Fe2O3）是一种应用很广的功能材料，研究用简便的方法制备性能良好的γ-氧化铁具有重要的实际意义。用柠檬酸盐凝胶法通过掺杂钠离子制备了粒径在20～30nm的γ-氧化铁纳米粒子。实验结果显示：热解过程中形成的碳酸钠对γ-氧化铁有较强的稳定作用，前驱物在450℃下热解1h，所得产物γ-氧化铁纯度高，团聚小；而不掺杂钠离子时，前驱物在相同的温度下热解，产物为纯α-氧化铁（α-Fe2O3）。另外还用X射线衍射（XRD）、透射电镜（TEM）等手段对产物进行了表征。

Nano - maghemite （ γ- Fe2 O3 ） is a functional material which has been widely used in various areas. Nano - maghemite with 20 - 30 nm particles were prepared by citrate - gel method through doping Na^＋. The test result showed that Na2CO3formed in pyrolysis process had the effect of stabilization on maghemite. When the precursors were calcined at 450 ℃ for 1 h, the γ- Fe2O3 with high purity and little agglomeration were obtained. In contrast, when the Na^＋ was not doped,the precursors were treated at the same temperature, the products were pure a - Fe2O3 . In addition,the products were characterized by XRD,TEM methods.