摘 要：采用直接共沉淀法制备（掺杂）α - Fe ₂O₃ 粉体并对其气 敏性能进行了初步研究。采用正交实验法将各实验参数（反应 物 Fe³⁺ 浓度、Sn⁴⁺/Fe³⁺ 摩尔比、反应液pH 值和烧结温度）有规律 组合，用直接共沉淀法制备出一系列刚玉型结构的（掺杂）α - Fe ₂O₃ 粉体，并用厚膜工艺将粉体涂在云母基片上制成了气敏元 件。通过对粉体的 XRD 测试与分析发现，部分 Sn⁴⁺ 以类质同象 方式进入到α- Fe ₂O₃ 晶格中，代替了Fe³⁺，改变了α- Fe ₂O₃ 的晶 胞参数；通过测试元件在不同温度下对甲烷的气敏性能，结果 表明，掺杂提高了α-Fe ₂O₃ 的气敏性，且得到了制备（掺杂）α Fe ₂O₃ 粉体的最佳参数。 

关键词: 直接共沉淀法；掺杂α - Fe ₂O₃ ；气敏材料

Abstract: The doped α-Fe₂O₃ powder has prepared by the direct co precipitation and gas-sensingmaterial wasstudied preliminarily.A series of doped α-Fe₂O₃ powders which have corundum structures were pre pared by direct co-precipitation method. The density of Fe³⁺, Sn⁴⁺/Fe³⁺molar ratio, pH and heat-treatment were combined regularly. The sensor was made by thick film technique with a α-Fe ₂O₃layer on mica-substrate. Fe³⁺in the crystal lattice of α-Fe ₂O₃ were partly re placed by Sn⁴⁺according to the XRD.It resulted in change of the lattice parameters. By testing and analyzing the sensitivities of methane at different temperatures, doping improved the sensitivity and the best parameters of preparing (doped) α-Fe₂O₃ were obtained. 

Keywords: direct co-precipitation；dopedα-Fe₂O₃；gas-sensingmaterial