Optical and magnetic properties of Ni-doped ZnO nanoparticles

• Published in: Journal of alloys and compounds Vol. 694; pp. 522 - 531
• Main Authors: Fabbiyola, S., Sailaja, V., Kennedy, L. John, Bououdina, M., Judith Vijaya, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.02.2017; Elsevier BV
• Subjects: Annealing; Chemical composition; Co-precipitation; Ferromagnetism; Magnetic properties; Nanoparticles; Ni-doping; Optical properties; Photoluminescence; Rietveld analysis; Spectral emissivity; Tween-80; Wurtzite; Zinc oxide; Tween-80; Ferromagnetism; Co-precipitation; Ni-doping; Rietveld analysis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.10.022

Zn1−xNixO with 0 ≤ x ≤ 0.2 nanoparticles (NPs) were prepared by co-precipitation with subsequent annealing at 500 °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. [Display omitted] •Presence of additional minor phase NiO was confirmed by Rietveld refinements.•Nanoparticles of large sheets, long rods, short rods, small sheets and small spheres were observed.•Strong and highly intense violet emissions were observed for all compositions of pure and doped ZnO.•Enhancement in remanence and coercivity was observed for Zn0.9Ni0.1O.•Magnetic measurements exhibit ferromagnetism, which was explained by BMP model.