Enhanced indirect ferromagnetic p-d exchange coupling of Mn in oxygen rich ZnO:Mn nanoparticles synthesized by wet chemical method
Rawat, Rajdeep Singh
Tan, T. L.
Date of Issue2012
School of Physical and Mathematical Sciences
This paper investigates the ferromagnetism in ZnO:Mn powders and presents our findings about the role played by the doping concentration and the structural defects towards the ferromagnetic signal. The narrow-size-distributed ZnO:Mn nanoparticles based powders with oxygen rich stoichiometery were synthesized by wet chemical method using zinc acetate dihydrate and manganese acetate tetrahydrate as precursors. A consistent increase in the lattice cell volume, estimated from x-ray diffraction spectra and the presence of Mn 2p3/2 peak at ∼640.9 eV, in x-ray photoelectron spectroscopic spectra, confirmed a successful incorporation of manganese in its Mn2+ oxidation state in ZnO host matrix. Extended deep level emission spectra in Mn doped ZnO powders exhibited the signatures of oxygen interstitials and zinc vacancies except for the sample with 5 at. % Mn doping. The nanocrystalline powders with 2 and 5 at. % Mn doping concentration were ferromagnetic at room temperature while the 10 at. % Mn doped sample exhibited paramagnetic behavior. The maximum saturation magnetization of 0.05 emu/g in the nanocrystalline powder with 5 at. % Mn doping having minimum defects validated the ferromagnetic signal to be due to strong p-d hybridization of Mn ions.
DRNTU::Science::Physics::Electricity and magnetism
Journal of applied physics
© 2012 American Institute of Physics. This paper was published in Journal of Applied Physics. and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.3679129]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.