Nickel disulfide films synthesized by sulfidation of nickel oxide film

Nickel Oxide films on gold substrates have been synthesized by sol–gel technique. Subsequently, the samples have been prepared by heat-treating the prepared nickel oxide films with sulfur in sealed quartz tubes at 400–800 °C. The crystal structures and micrograph of the samples have been characterized by X-ray diffraction (XRD) and scanning electron microscopy respectively, the nickel contents of samples have been determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results show that: the crystal structures of the film samples prepared by heat-treating the nickel oxide films and sulfur at 400–600 °C are nickel disulfide (NiS2) with the pyrite structure, the average value of the cell constant a is 5.69 Å calculated from the XRD peaks of the synthesized nickel disulfide films, and the average crystallite size of the nickel disulfide is 60 nm estimated from the Scherrer equation. After sulfurization of the NiO film at 700–800 °C, there is loss of nickel contents from the Au substrate due to vaporization of the nickel sulfide.

Nickel content of the formed film at different temperatures. The nickel sulfide can vaporize at 700–800 °C.Figure optionsDownload as PowerPoint slide