Mn-dopant-induced effects in Zn_1−xMn_xO compounds

An experimental study on Mn-dopant-induced effects in Zn_1−xMn_xO was performed for samples with x = 0.02, 0.04, 0.06, and 0.08, which were prepared by solid state reaction at 1200 °C. The result of x-ray diffraction refinement analysis did not turn up evidence of Mn_xO_y cluster inclusion over the entire doping range, while the structural parameter variations indicate a solubility limit of about 6% for Mn²⁺ and incorporation of Mn ions of higher valency at higher dopant levels. The magnetization data exhibit mostly intrinsic antiferromagnetic instead of ferromagnetic properties, as predicted by more recent theoretical works. The substitutional incorporation of the Mn in ZnO was further confirmed by the associated broad-band photoluminescence spectra. The suggested incorporation of Mn ions of higher valency at higher dopant concentration was also supported by the related x-ray photoemission data, and in agreement with a previous theoretical prediction.