Study of a Cr doped TiO/sub 2/ derived from sol-gel process for gas sensing

The sol-gel route to thin bimetallic oxide sensor films was studied in terms of the evolution of a viscoelastic Ti gel precursor containing occluded Cr. The influence of Cr:Ti atomic ratio and annealing temperature was related to the resultant microstructure, morphology and oxygen sensing response of the annealed thin films. It was shown that progressive increase in Cr content changed the Ti-O properties from a n-type to a p-type semiconductor film with a commensurate reversal in sensor response.