Gas-sensitive properties and structure of nanostructured (alpha-Fe2O3)(x)-(SnO2)(1-x) materials prepared by mechanical alloying

The gas-sensitive properties of nanostructured 94, 85, 71 and 7 mol% alpha-Fe2O3SnO2 materials prepared by high-energy hall milling have been investigated in atmospheres containing alcohol, CO and CH4 gases. It has been found that the materials show a high sensitivity with a short response time to the alcohol gas and almost no sensitivity to the other two gases, CO and CH4 in the concentration ranges studied. Furthermore, the gas-sensitive behaviour of these materials in response to the alcohol gas has been discussed on the basis of the microstructure of the materials. It is found that the tin ion content in alpha-Fe2O3 and tin ions on the surface of alpha-Fe2O3 particles may play an important role in the enhancement of the gas sensitivity.