Influence of Co ions doping in structural, vibrational, optical and magnetic properties of ZnO nanoparticles

In this present work, the Co²⁺ ions doping effect on the structural, vibrational, morphological, optical and magnetic behavior of ZnO nanoparticles (NPs) are reported. The Zn_1−xCo_xO (with 0 ≤ x ≤ 0.05) samples were prepared by co-precipitation method. The single crystalline phase was identified as the Wurtizite structure and doping effect of prepared NPs was confirmed by XRD. In addition, a small peak shifts and variation of peak intensity have been found on Co²⁺ doping increases. Further, the prepared samples were characterized by Raman spectra, photoluminescence (PL), UV–Drs, FTIR, XPS spectroscopic measurements. The structural change and presence of defects were confirmed by Raman spectra and PL analysis. The optical properties exhibit the incorporation of dopant ions and their effect on the band gap subsequently. The XPS analysis confirmed the valence state of the dopant ions in the ZnO matrix. The observed room temperature ferromagnetism and the non-monotonic variation in the magnetic properties were discussed based on the presence of intrinsic defects in the prepared samples.