There are many techniques for obtaining samples, different results have been reported for the magnetic properties. For instance, Janisch et al. [22] found that Fe-doped ZnO indicated a paramagnetic behavior whilst Polyakov et al. [23] reported a room temperature ferromagnetism by doping Fe ions in ZnO crystal derived by vapor phase. Variations in magnetic properties for Fe-doped ZnO indicated that ferromagnetism of such a system might strongly depend on the methods and conditions used in the preparation.