Optical and magnetic properties of Ni-doped ZnO nanoparticles

Zn1-xNixO with 0 <= x <= 0.2 nanoparticles (NPs) were prepared by co-precipitation with subsequent annealing at 500 degrees C for 2 h. For a better control of particle's growth, a non-ionic surfactant namely Tween-80 was used during the preparation process. XRD Rietveld analysis confirmed the formation of the hexagonal wurtzite-type structure along with a secondary phase namely NiO. SEM observations revealed remarkable change in morphology, including rods, sheets and spheres. The purity of the as prepared NPs as checked by EDAX analysis indicated that the chemical composition of Zn, Ni and O was in good agreement with the starting stoichiometries. The defect states were revealed from the UV and visible emissions of the photoluminescence spectra. The DRS analysis showed blue shift as Ni2+ increases from 5 to 20%. The existence of a peak at 432 cm(-1) in FTIR spectra confirmed the formation of ZnO phase. The Magnetization-Field (M-H) curves revealed the existence of ferromagnetism in Ni-doped ZnO NPs, which was attributed to bound magnetic polaron (BMP) mechanism. (C) 2016 Elsevier B.V. All rights reserved.