Influence of oxidant to fuel ratio on the structural and optical properties of In 2 O 3 nanoparticles synthesized by auto-combustion method

Abstract The effect of fuel (Glycine, G) to oxidant (metal Nitrates, N) ratio on the formation of nano-sized powders by the self-propagating auto-combustion technique is reported. Nano-crystalline single phase In 2 O 3 was synthesized at different G/N mole ratio. 0.5 to 2.5. The powders obtained by auto-combustion were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance UV/Vis/NIR spectrometer. The crystallite size of as synthesized powder was found to be around 11 nm for fuel lean composition. The optical studies by Kubelka–Munk analysis exhibited the variation of band gap from 2.92 eV to 3.26 eV. The lattice parameters, stress and inter planar spacing were also evaluated. Thus the G/N ratio is important for successful preparation of nano-crystalline indium oxide.