Structural characterization and magnetic properties of Co co-doped Ni/ZnO nanoparticles

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2016-02, Vol.122 (2), p.1-11, Article 122
• Main Authors: Vijayaprasath, G., Murugan, R., Asaithambi, S., Babu, G. Anandha, Sakthivel, P., Mahalingam, T., Hayakawa, Y., Ravi, G.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Cobalt; Condensed Matter Physics; Ferromagnetism; Ion exchange; Machines; Magnetic properties; Manufacturing; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Synthesis (chemistry); Thin Films; Wurtzite; Zinc oxide
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-016-9655-0

In this paper, we present the structural, morphological, optical and magnetic properties of Zn 1− x A x O ( A  = Ni, Co and x  = 0.20 mol%) and Zn 0.80 Ni 0.10 Co 0.10 O nanoparticles synthesized by a chemical co-precipitation method. Powder X-ray diffraction data confirm the formation of a single-phase wurtzite-type ZnO structure for all the samples. FTIR and EDS measurements ensure that the divalent Ni and Co ions are incorporated in the wurtzite host matrix without any impurity phase. Photoluminescence and Raman spectra indicate the presence of donor defects and oxygen vacancies in the prepared samples. In VSM analysis, undoped ZnO nanoparticles exhibit diamagnetic behavior at room temperature. A systematic increase in ferromagnetic moment (~0.70 emu/g) is observed for Ni-, Co-doped and Co co-doped Ni/ZnO at 300 K. The exchange interaction between delocalized carriers and the localized ‘d’ spins of Ni and Co ions is predicted as the cause of the room temperature ferromagnetism.