No ferromagnetic properties in polycrystalline Al-doped Zn0.97Mn0.03O diluted magnetic semiconductor

Zn0.96Mn0.03Al0.01O powders have been synthesized using the co-precipitation technique. X-ray diffraction patterns show the typical würtzite structure with no additional peaks for all samples. Raman spectroscopy revealed that Mn2+ ions were substituted for Zn2+ into the ZnO matrix and that Al and Mn ions activate an additional vibration mode at 670 cm− 1 which is specific to interstitial defects. The resistance measurements give a confirmation of the presence of free carriers. Nevertheless, magnetization measurements revealed only a mixture of paramagnetic and antiferromagnetic behaviors for all samples with no sign of ferromagnetism.