Polyol synthesis of α-NiS particles and its physico-chemical properties

Using simple and low cost polyol method, α-NiS particles are synthesized at different pH conditions (pH 7–pH 14). Single phase formation and possible functional groups of α-NiS are identified through X-ray diffraction (XRD), and Fourier transforms infrared (FT-IR) spectroscopy, respectively. Further, X-ray photoelectron spectroscopy (XPS) clearly reveals the phase purity of α-NiS particles. Scanning electron microscopic (SEM) images reveals the presence of pseudo-spherical particles within the size range of 200–400 nm. Subsequently, the grain size alters the optical and electrical properties of the samples significantly. Similarly, α-NiS prepared at pH 8 provides high dielectric constant (2.3×104), and low dielectric loss (13×103), than the sample prepared at pH 7 of α-NiS.