材料期刊网

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，而缩合催化剂钛酸丁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，最终产物为和氧化铁的混晶相(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 nanocrystalα-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.