Structural and Magnetic Characterization of Mn and Fe-doped ZnO Nanopowders

The Zn_1-xA_xO (A = Mn, Fe and x = 0 - 0.03) nanopowders, have successfully been synthesized by coprecipitation method. The starting materials of dihydrate zinc acetate, iron and mangan powders were employed using HCl and NH₄OH as solvent and precipitating agents respectively. The solution was stirred at 48°C for 4h to induce a precipitation and the resulted precipitate was then heated at 100°C for 24h in air followed by annealing at 400°C for 3h. Based on the XRD spectra, the doped samples with x up to 0.02 form the single wurtzite phase of ZnO with crystal size around 20-60 nm, where the dopants, both Mn and Fe, have partially substituted Zn. Meanwhile, samples with x = 0.03 were obesrved to contain impurity phases. The magnetization for the magnetic field up to 1 tesla vizualizes a monotonically increased weak-ferromagnetism for Fe doping, while exhibits from diamagnetic, paramagnetic to weak-ferromagnetic behaviors for Mn doping. This magnetic interaction becomes complicated by the presence of magnetic impurities due to Mn dopant.