Experimental and first‐principle investigation of Cu‐doped ZnO ferromagnetic powders

Zn 1‐ x Cu x O powders were synthesized by using sol‐gel method. Electronic band structure and ferromagnetic properties of Zn 1‐ x Cu x O powders were studied experimentally and theoretically. The simulations are based upon the Perdew‐Burke‐Ernzerhof form of generalized gradient approximation within the density functional theory. Zn 1‐ x Cu x O shows dilute ferromagnetism, as a saturated magnetization of 0.9×10 ‐3 emu/g was observed for Zn 0.95 Cu 0.05 O powders. The strong p ‐ d hybridization between Cu and its four neighbouring O atoms is responsible for the ferromagnetism. Comparing with ZnO whose Fermi level locates at the valence band maximum, the Fermi level of the Zn 1‐ x Cu x O shifts upward into the valence band and hence the Zn 1‐ x Cu x O system exhibits theoretically a p ‐type metallic semiconducting property. The Zn 1‐ x Cu x O system may be a potential candidate in spintronics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)