Doping effects of Co2+ ions on structural and magnetic properties of ZnO nanoparticles

In this paper, we report the synthesis of Zn1−xCoxO (0.0 ⩽ x ⩽ 0.10) nanoparticles by an auto-combustion method using glycine as a fuel. The prepared nanoparticles were characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and DC magnetization measurements. XRD results showed that Co doped ZnO have a single phase nature with wurtzite structure and Co2+ ions were successfully incorporated into the lattice position of Zn2+ ions in ZnO matrix. FTIR spectra demonstrated that the values of absorption bands were blue shifted with the increase of Co content. From the Raman spectra, all the peaks observed in undoped and Co-doped samples can be assigned to the Raman active modes of ZnO crystal. However, in case of Co doped ZnO sample, additional modes were observed that can be related to the substitution of Co into the Zn site. Magnetic studies showed that Co doped ZnO nanoparticles exhibit room temperature ferromagnetism.

We report the synthesis of Zn1−xCoxO (0.0 ⩽ x ⩽ 0.10) nanoparticles by an auto-combustion method. XRD results showed that Co doped ZnO have a single phase nature with wurtzite structure and Co2+ ions were successfully incorporated into the lattice position of Zn2+ ions in ZnO matrix. FESEM results revealed that the prepared Co-doped ZnO nanoparticles were nearly spherical in shape with particle size <50 nm, which was in good agreement with the size obtained from XRD. Magnetic studies showed that Co doped ZnO nanoparticles exhibit room temperature ferromagnetism.Figure optionsDownload as PowerPoint slideHighlights
► We prepared pure and Co-doped ZnO nanoparticles using auto combustion route.
► XRD and FT-IR indicates that un-doped and Co-doped ZnO have wurtzite structure.
► No secondary phase was detected which indicated that Co ions substituted for Zn ions.
► Major Raman mode (E2high) has blue shift with the increase in Co doping.
► Co doped samples showed room temperature ferromagnetism.