电弧等离子体法制备的纳米α-Fe_(2)O_(3)的气敏特性

Property of Gas Sensitivity of α-Fe_(2)O_(3) Prepared by Plasma Method

用电弧等离子体法制各纳米α－Ｆｅ＿２Ｏ＿３并研究其气敏特性，结果表明，在没有掺杂的情况下，纳米α－Ｆｅ＿２Ｏ＿３就具有较好的气敏特性。其原因是纳米粒子具有较大的比表面积和较高的晶界比例，从而导致对气体的吸附能力和扩散能力增强。本文用原位ＸＲＤ方法研究了纳米α－Ｆｅ＿２Ｏ＿３的气敏机理，结果表明，在还原性气氛和加热条件下，α－Ｆｅ＿２Ｏ＿３并没有被还原成Ｆｅ＿３Ｏ＿４，其气敏机理主要是表面效应控制型。

Nanometer α-Fe_2O_3 was prepared byarc plasma method and its gas sensitivity wasstudied.The results show that nanometer α-Fe_2O_3without any dopant possesses very good properties ofgas sensor.This mainly comes from the fact thatnanometer particles have large speciflc surface areaand high ratio of crystal boundary,which leads tostrong adsorption and high diffusion ability to gases.The mechanism of gas sensitivity of nanometer α-Fe_2O_3 was studied by the in situ XRD method.Theresults show that the mechanism of gas sensitivity ofα-Fe_2O_3 is surface controlled type rather than phasetransformation controlled type.