Tinku Ali

Enhanced room temperature ferromagnetism in Ni doped SnO2 nanoparticles: A comprehensive study

We emphasized on a detailed investigation of the structural, optical, and magnetic properties of pure and Ni-doped SnO2 nanoparticles (NPs) synthesized by a sol-gel process. An extensive structural study has been carried out using various characterization techniques. The X-ray Diffraction (XRD) spectra show the formation of the single phase tetragonal structure of pure and Ni-doped SnO2 NPs without any noticeable impurity phase such as NiO. XRD results indicate that the crystallite size of SnO2 is found to be decreased with Ni doping, which has also been confirmed by the Field Emission Scanning Electron Microscopy study. X-ray Photoelectron Spectroscopy (XPS) measurements displayed a clear sign for Ni2+ ions occupying the lattice sites of Sn4+ in the SnO2 host which also gives clear evidence for the formation of single phase Sn1-xNixO2 NPs. The optical analysis shows a significant decrease in the energy gap of SnO2, i.e., (from 3.71 eV to 3.28 eV) as Ni concentration increases which may be correlated with...

Structural phase analysis, band gap tuning and thermal properties of TiO2/ZnO nanocomposite

The present work emphasizes the structural, optical and thermal properties of pure TiO2 and TiO2/ZnO nanocomposite. The samples were synthesized by sol–gel method and characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Ultraviolet-visible spectroscopy and Thermal gravimetric analysis (TGA). The XRD analysis shows that synthesized TiO2 nanoparticles consisted of only anatase phase and also it revealed the presence of both, TiO2 and ZnO phases in TiO2/ZnO nanocomposites. TEM analysis confirmed that the shapes of TiO2/ZnO nanocomposite are spherical (due to TiO2) and nanorods (due to ZnO) and EDS analysis confirmed that synthesized material has no impurity. Thermal gravimetric analysis (TGA) shows the weight loss of the nanoparticles which is found to take place up to 800°C, beyond this temperature no significant weight loss was observed. The band gap of pure TiO2 and TiO2/ZnO nanocomposite have been estimated from absorption peak a...

Polyethylene glycol (PEG) assisted size-controlled SnO2 nanoparticles by sol-gel process

Tetragonal phase tin oxide (SnO2) nanoparticles have been synthesized by sol–gel method using SnCl4.5H2O and polyethylene glycol (PEG) of different concentration. The phase, size and purity of the final products are characterized by X-ray diffraction (XRD). The morphology is confirmed by scanning electron microscopy (SEM) analysis. There exists relationship between the concentration of PEG and particle size of SnO2 nanoparticles. Increase in concentration of PEG caused the reduction of particle size of tin oxide nanoparticles. The results suggest that the concentration of PEG plays a significant role in determining the size of SnO2 nanoparticles synthesized via this method. The optical property of the product has been explored by Ultraviolet (UV-visible) and Fourier Transform Infrared (FTIR) spectroscopic techniques.

Influence of Fe ions on structural, optical and thermal properties of SnO2 nanoparticles

In the present work, Fe doped SnO2 nanoparticles with the composition Sn1-xFexO2 (x = 0, 0.02, 0.04 and 0.06) have been successfully synthesized using sol-gel auto combustion technique. The samples are characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDAX), Ultraviolet (UV-Visible) absorption spectroscopy and thermal gravimetric analysis (TGA). The XRD study shows that all the samples have been found in tetragonal rutile structure without any extra phase and average crystallite size which lies in the range of 6-17 nm. The EDAX spectrum confirmed the doping of Fe ion into tin oxide nanomaterial. The optical band gap of doped SnO2 is found to decrease with increasing Fe ion concentration, which is due to the formation of donor energy levels in the actual band gap of SnO2.