Investigation of impurity phase formation for (ZnO)1−x(TMO)x bulk samples formed by ball milling

Structural, compositional, optical and magnetic properties have been studied for polycrystalline (ZnO)0.90(TMO)0.10 bulk samples, where TM (transition metal ions) = Mn, Fe, and Co. The quantitative Rietveld analysis showed relatively higher percentage of impurity (spinel and oxide) phases of about 33.76, 52.38 and 55.61% for Mn, Fe and Co doped ZnO samples, respectively. The de-convolution of XPS spectra indicated the presence of different phases. The appearance of shaking satellites in XPS spectra confirmed the presence of different valence states of dopant ions. The red shift in energy band gap, estimated from reflectance UV-vis spectroscopy, was observed for all TM doped bulk samples. For Mn doping, paramagnetic behavior was obtained while for Co and Fe, weak ferromagnetic behavior was observed at room temperature.