Electron paramagnetic resonance in Zn1−xCoxO

• Published in: Journal of magnetism and magnetic materials 2013-03, Vol.329, p.39-42
• Main Authors: Acosta-Humánez, F., Cogollo Pitalúa, R., Almanza, O.
• Format: Article
• Language: English
• Subjects: Citrates; Cobalt; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Curie–Weiss temperature; Diffraction; Electron paramagnetic resonance; Electron paramagnetic resonance and relaxation; EPR; Exact sciences and technology; Exchange and superexchange interactions; Ferromagnetic materials; Ferromagnetism; Free radicals; Magnetic properties and materials; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Magnetic semiconductors; Magnetically ordered materials: other intrinsic properties; Physics; Sol–gel method; Studies of specific magnetic materials; X-rays; ZnO
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.10.026

In this paper is reported the Electron Paramagnetic Resonance (EPR) studies in Zn1−xCoxO powder, with 0.01≤x≤0.05, at many temperatures (105–250K). These samples were synthesized by the sol–gel method (citrate route). Results suggest that the ferromagnetism behavior of the materials is governed by ferromagnetic coupling among cobalt ions. For cobalt concentration higher than 3% were obtained mean size particle higher than 25nm, measured by X-ray diffraction, and for this were also observed shallow free radical. ► Zn1−xCoxO with 0.01≤x≤0.05 were synthesized by sol–gel method (citrate rute). ► For Co concentration higher than 3% the mean size particle are higher than 25nm. ► There are shallow free radicals when the mean size particle is higher than 25nm. ► Ferromagnetism is the behavior in Co-doped ZnO.