Gunjan Srinet

Structural, optical, vibrational, and magnetic properties of sol-gel derived Ni doped ZnO nanoparticles

With a view to study structural, optical, vibrational, and magnetic properties of solgel derived Zn1−xNixO (x = 0.02, 0.04, and 0.06) nanoparticles, systematic investigations have been carried out. The Rietveld refinement of X-ray powder diffraction data revealed a single hexagonal phase with space group P63mc. The secondary phase of NiO appeared only in 6% Ni doped sample. Phonon modes in Ni doped ZnO nanoparticles were studied through Fourier transform infrared measurements. Furthermore, the enhancement in optical band gap with Ni doping from 3.29 to 3.32 eV has been observed through UV-visible spectroscopic analysis. Photoluminescence spectra of Zn1−xNixO show the UV-emission peak showing the blue shift with increase in doping concentration followed by broad visible (blue) emission corresponding to the defect emission whose intensity decreased with increasing Ni concentration. A clear room temperature ferromagnetism is observed in all samples but saturation magnetization decreased with increasing Ni co...

Effects of Mg doping on the structural and optical properties of ZnO nanoparticles

Mg doped ZnO (ZnxMg1−xO, x=0.02, 0.06 and 0.1) nanoparticles were successfully prepared by thermal decomposition method. Reitveld analysis of the XRD data confirmed the wurtzite structure and the continuous change in lattice parameters. Absorption spectra revealed a blue shift in the energy band gap and photoluminescence studies show a sharp and dominant peak corresponding to the near band edge emission in ultra violet range and a broad band in the range 420-600 nm corresponding to defects and oxygen vacancies which increased with doping concentration. Fourier transform infrared measurements were carried out to study phonon modes in Mg doped ZnO nanoparticles.

Structural studies and band gap tuning of Cr doped ZnO nanoparticles

Structural and optical properties of Cr doped ZnO nanoparticles prepared by the thermal decomposition method are presented. X-ray diffraction studies confirmed the substitution of Cr on Zn sites without changing the wurtzite structure of ZnO. Modified form of W-H equations was used to calculate various physical parameters and their variation with Cr doping is discussed. Significant red shift was observed in band gap, i.e., a band gap tuning is achieved by Cr doping which could eventually be useful for optoelectronic applications.

Effect of Ni doping on the structural, optical and magnetic properties of Zno

The effect of Ni doping on the structural, optical and magnetic properties of sol-gel derived Zn1−xNixO (x=0.02, 0.06 and 0.06) samples have been investigated. The single-phased wurtzite structure is confirmed by XRD analysis. The crystalline nature of the samples was confirmed by SEM measurements. The Photoluminescence spectra exhibited the shift in the near band edge emission towards the lower wavelength side with increasing Ni-concentration, which can be explained by the Burstein-Moss effect. Room temperature ferromagnetism is observed in all the samples.