直接共沉淀法制备掺杂α-Fe_2O_3及其气敏性能的初步研究

Preliminary Study on Preparation and Gas-sensitivity of Doped-Fe_2O_3 Material by Direct Co-Precipitation Method

采用直接共沉淀法制备(掺杂)α-Fe2O3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-Fe2O3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-Fe2O3晶格中,代替了Fe3+,改变了α-Fe2O3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-Fe2O3的气敏性,且得到了制备(掺杂)α-Fe2O3粉体的最佳参数。

The doped α- Fe2O3 powder has prepared by the direct coprecipitation and gas-sensing material was studied preliminarily. A series of doped α-Fe2O3 powders which have corundum structures were prepared by direct co-precipitation method. The density of Fe^3＋, Sn^4＋/Fe^3＋ molar ratio, pH and heat-treatment were combined regularly. The sensor was made by thick film technique with a α- Fe2O3 layer on mica-substrate, Fe^3＋ in the crystal lattice of α- Fe2O3 were partly replaced by Sn^4＋ 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.