ABSTRACT
Metal oxides have numerous technological applications and provide an excellent platform to study various fundamental physical processes and phenomena existing in the material systems. Metal oxides crystallize in a multitude of crystal structures and exhibit diverse properties. For example, several metal oxides have the ability to undergo reversible surface oxidation and reduction processes due to the adsorption of certain speci c gases (Henrich and Cox 1994). e adsorption of gas molecules results in band bending at the surface and e ectively modi es the surface conductivity. Such a change in the conductivity due to gas adsorption is readily detectable in most of the metal oxides, including SnO2, In2O3, and ZnO. Deviations in the properties of metal oxides due to the adsorption of speci c gases render them as potential gas sensors. Transition metal oxides, in particular, are attractive for their range of properties (Rao 1999). is is partly due to the partially lled d-orbital and the mixed valency of the constituent transition metal atoms and the defect-induced self-doping capability. Transition metal oxides are potentially useful in a variety of applications including as a catalysis in the petroleum industry, magnetic data storage in information technology, and gas sensing.
