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% a lpha-Fe2O3SnO2 materials prepared by high-energy hall milling have bee n investigated in atmospheres containing alcohol, CO and CH4 gases. It has been found that the materials show a high sensitivity with a shor t response time to the alcohol gas and almost no sensitivity to the ot her two gases, CO and CH4 in the concentration ranges studied. Further more, the gas-sensitive behaviour of these materials in response to th e 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 an d tin ions on the surface of alpha-Fe2O3 particles may play an importa nt role in the enhancement of the gas sensitivity.