Effect of ferromagnetic properties in Al-doped Zn1-x Cox O nanowires synthesized by water-assistance reactive vapor deposition

Abstract

The Zn1-x Cox O and Al-doped Zn1-x Cox O nanowires have been synthesized by the water-assistance reactive vapor deposition method. No Co precipitates appeared in the both kinds of ZnO nanowires according to the results observed by high-resolution transmission electron microscope, x-ray diffraction, and electron energy-loss spectroscopy, revealing that the magnetism of the ZnO nanowires was independent of the Co precipitates. The Al-doped Zn1-x Cox O nanowires show much stronger ferromagnetism than Zn1-x Cox O nanowires in the temperature range of 4-350 K. It is believed that the ferromagnetism in Zn1-x Cox O nanowires could be enhanced by Al doping to introduce donor carriers. Moreover, a multiple mechanism for the ferromagnetism of Al-doped Zn1-x Cox O nanowires is discussed. © 2007 American Institute of Physics.