Mn-doped ZnO nanonails and their magnetic properties.

Mn-doped ZnO nanonails composed of hexagonal caps and shafts with large doping concentrations from 11.7 to 35.1 at.% were synthesized via a simple and straightforward non-aqueous solution-based route. The chemical composition, morphology and structure of the obtained nanocrystals were characterized by energy-dispersive x-ray analysis, powder x-ray diffraction and transmission electron microscopy. The results show that the nanonails possess a single-crystal wurtzite structure. Electron paramagnetic resonance results indicate that Mn(2+) ions substitute for the zinc sites in the ZnO matrix, which is also confirmed by high-resolution electron microscopy. Thermal tolerance experiments show that the Mn-doped nanonails can maintain their crystalline structure up to 700 degrees C. The influence of reaction conditions on the size and shape of the ZnO-based samples has been investigated in detail, and the possible growth mechanism of the nanonails has also been discussed.