【摘要】 在硝酸铁乙二醇甲醚溶液体系中加入硅酸乙酯，用溶胶一凝胶法制备γ-Ｆｅ＿２Ｏ＿３纳米晶粉体．硅酸乙酯的加入不但加速凝胶化过程，而且有效抑制氧化铁晶粒的生长，提高γ-Ｆｅ＿２Ｏ＿３向γ-Ｆｅ＿２Ｏ＿３转变的相变温度．ＴＧ－ＤＴＡ热分析结果表明这个相变温度为７００℃左右．改变硅酸乙酯的加入量可制备出具有不同晶相的粉体；ＴＥＭ观测表明粉体的粒径约为 １０ｎｍ．γ-Ｆｅ＿２Ｏ＿３纳米晶粉体的气敏特性具有迅速的响应一恢复性能，掺人少量Ｚｎ可改善气敏特性．更多还原

【Abstract】 The nanocrystal 7-Fe2O3 wa5 prepared by sol-gel method in iron nitrate and 2- methoxyethanol syStem. Adding ethyl orthosilicate not only decrease the gelation time but prevent iron oxide nanocrystal growing and increase the phase transfer (from 7 to a) temperature to about 700 t, which is useful to fOrm 7-Fe2O3 with good thermostability XRD analysis and TEM observation show that different materials can be obtained by changing ethyl orthosilicate amount and the average particle size is about 10nm. The sensitive mechanism of materiaIs to gas is bulk resistance domination including a part of suface resistance domination. Doping Zn can increase the sensitivity The materials have fast response and reversion characteristics.更多还原