研究了在硝酸铁乙二醇甲醚溶液体系中，用溶胶－乳化－凝胶法制备氧化铁纳米晶，首次将表面活性剂（ＳＤＳ）引入溶胶－凝胶化过程，并采用一种高效缩合催化剂来加速此过程．结合ＴＥＭ、ＸＲＤ和ＴＧ－ＤＴＡ分析手段对产物进行了表征，结果表明，加入的表面活性剂（ＳＤＳ）有助于纯相α－Ｆｅ２Ｏ３纳米晶的生成，而缩合催化剂钛酸了酯的加入则大大缩短凝胶时间，所得粉体的原始晶粒尺寸为３０ｎｍ左右．若以常用的硅酸乙酯代替钛酸丁酯，则胶凝时间明显延长，最终产物为β和α氧化铁的混晶相（γ－Ｆｅ２Ｏ３为主晶相），晶粒尺寸约为１０ｎｍ，并从中提出了一条改进γ－Ｆｅ２Ｏ３基气敏材料性能的新思路．
The nanocrystal α-Fe2O3 with an average size of about 30nm was prepared by a sol-emulsify-gel method in
the iron nitrate and 2-methoxyethanol system. The powders were characterized by TEM, XRD and the xerogel primary powders thermal stability was studied by
TG-DTA. The gelation time was reduced greatly by adding tetrabutyl titanate. When tetraethyl orthosilicate instead of tetrabutyl titanate, the gelation
time can be much longer. γ-Fe2O3 with spinel structure appeared as the main phase in the calcinated powder and the average particle size
was about 10nm. A new idea to improve the gas sensitivity and stability of γ-Fe2O3 gas-sensitive materials was provided. The results show
that the introduction of surfactant(SDS) is helpful to form pure crystal phase α-Fe2O3.
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