Room-temperature ferromagnetism in (Mn, N)-codoped ZnO thin films prepared by reactive magnetron cosputtering

(Mn, N)-codoped ZnO films were grown on fused silica substrates by reactive magnetron cosputtering. X-ray diffraction measurements reveal that the films have the single-phase wurtzite structure with c-axis preferred orientation. X-ray photoelectron spectroscopy studies indicate the incorporation of both divalent Mn2+ and trivalent N3- ions into ZnO lattice. Acceptor doping with nitrogen partly compensates the native donors, which results in a low electron concentration of 3.16x10(16) cm(-3) though p-type conductivity is not achieved. (Mn, N)-codoped ZnO films show significant ferromagnetism with Curie temperature above 300 K. The mechanism of ferromagnetic coupling in codoped ZnO is discussed based on a bound magnetic polaron model. (c) 2006 American Institute of Physics.