Effect of Al and Sb doping on the magnetic properties of ZnMnO and ZnCoO

The bulk polycrystalline samples with nominal compositions Zn0.98-y(Mn/Co)(0.02) (Al/Sb)(y)O (y = 0, 0.01, and 0.03) have been synthesized via solid state reaction route. The x-ray diffraction results reveal the presence of mainly wurtzite structure of pure ZnO in all the Al/Sb codoped ZnMnO and ZnCoO samples. EDAX results confirm the presence of all elements in the samples in the stoichiometric ratio. While the Zn(Mn/Co)O samples show paramagnetic behavior at room temperature, the Al/Sb codoped ZnMnO samples exhibit room temperature ferromagnetism (RTFM) with saturation magnetization (Ms). The M-H curves of Al/Sb codoped ZnCoO samples show almost linear variation with a small kink at the origin, indicating the presence of weak ferromagnetism in the Al/Sb codoped ZnCoO samples. Possible mechanisms of the observed RTFM in Al/Sb codoped Zn(Mn/Co)O samples are discussed in this paper. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3059408]