Structures and magnetic properties of (Mn, N)-codoped ZnO thin films

Zn 0.96 Mn 0.04 O and Zn0.96Mn0.04O:N thin films with wurtzite structure were grown by inductively coupled plasma enhanced chemical vapor deposition method. Although both samples exhibit ferromagnetism at room temperature, the saturation magnetic moment (1.4μB∕Mn) of the Mn- and N-codoped sample is much larger than that (0.3μB∕Mn) of the N-free one. The x-ray absorption near edge structure analysis reveals that the codoped Mn and N impurities can be substitutionally incorporated into the ZnO host in the Zn0.96Mn0.04O:N thin film. The first-principles calculations suggest that the N substitution for the O site in Mn-doped ZnO can change the interaction of neighboring Mn–Mn pairs from antiferromagnetic to ferromagnetic, and accordingly the effective magnetic moment per Mn is greatly enhanced.