Monocrystalline Ni-doped ZnO nanorods were synthesized through a chemical

method. The average length and diameter of these nanorods were in the ranges of

400–700nm and 25–40nm, respectively. Structural analyses revealed that the Nidoped

ZnO nanorods were of pure wurtzite hexagonal phase and grew along the

preferred c-axis direction. X-ray photo-electron spectroscopy gives evidence that

the Ni dopant was in the +2 valence oxidation state and was uniformly distributed

in the nanorods. Full multiple-scattering ab initio calculations of Ni K-edge X-ray

absorption near edge structure analysis revealed that Ni impurity atoms were

substitutionally incorporated into ZnO host without formation of secondary phases

(Ni metal and Ni2O3). The comparison of experimental and simulated X-ray

absorption near edge structure spectra on Ni K edge revealed the presence of the oxygen vacancy (native defect) in the prepared nanorods. Photoluminescence

spectrum exhibited two emission peaks, which were ascribed to near band edge

transitions and broadened intensive green emission associated with oxygenvacancy

defects. Furthermore, the magnetic measurements revealed that the

nanorods exhibit intrinsic room-temperature ferromagnetism. Ferromagnetic

ordering was interpreted by the overlapping of polarons mediated through oxygen

vacancy based on the bound magnetic polaron model.

Oxygen-Vacancy-Induced Green Emission and Room-Temperature

Ferromagnetism in Ni-Doped ZnO Nanorods. J.Iqbal, B.Wang, X.Liu, D.Yu,

B.He, R.Yu: New Journal of Physics, 2009, 11[6], 063009