Soft-chemical preparation and gas sensing properties of iron and manganese substituted Cr1.8Ti0.2O3+δ

Compounds of nominal compositions Cr1.8Ti0.2O3+δ, Cr1.7Fe0.1Ti0.2O3+δ and Cr1.78Mn0.02Ti0.2O3+δ have been prepared by a co-precipitation method and characterized by X-ray powder diffraction and thermal analyses. The sensor characteristics of these nominal compositions are reported. The sensors fabricated using the powders calcined at 773, 873, 973 and 1273 K were tested for their sensing properties towards ammonia, hydrogen and liquefied petroleum gas (LPG). The influence of calcination temperature and the incorporation of iron and manganese oxides in enhancing the sensitivity are discussed.