Synthesis and Room Temperature Ferromagnetism of Flower-shaped Mn Doped ZnO Nanostructures

Large-scale flower-shaped Mn doped ZnO nanostructures have been grown on silicon substrates by simple thermal evaporation at atmospheric pressure. The flower-shaped nanostructure makes up of many nanorods, which are rooted in one center. Analysis of X-ray diffraction, high-resolution transmission electron microscopy and Raman spectra results reveal that the products are of single phase with wurtzite structure. Elemental mapping results show that no impurity clusters exist in the doped materials. The photoluminescence spectra demonstrate that many oxygen vacancies exist in the doped materials, and the crystal quality is improved and the content of oxygen vacancies is decreased by annealing treatment. The flower-shaped Mn doped ZnO nanostructures exhibit ferromagnetic ordering above room temperature, and its magnetization is decreased by the annealing treatment, which indicates that the magnetic behavior of the doped materials may be related to the interaction between Mn doping and the oxygen vacancies.