NiO nanostructure by RF sputtering for gas sensing applications

A nanostructured thin film of NiO with thickness (1250 +/- 30) nm was synthesized using the RF-reactive planer magnetron sputtering technique over a cleaned glass substrate. Structural analysis of the nanostructured NiO films was conducted utilising the XRD method, and the films were found to have a polycrystalline nature with a preferred (200) plane reflection at the angle 2 theta equal to 43.35 & x1d52;. The optical measurement for NiO thin films manifested the transmittance, the energy band gap and the absorption coefficient in the ultraviolet and visible regions. A scanning electron microscope (SEM) was used to analyses the surface morphology of the NiO thin film sample. The ability of nanostructured NiO thin films to sense different NO2 gas concentrations in terms of the time working was studied and reported. The nanostructured NiO film had better sensitivity at the gas ratio of 350 ppm and the operating temperature 150 & x1d52;C.