Room-temperature ferromagnetism in p-type nitrogen-doped ZnO films

Ferromagnetism in p-type N-doped ZnO films, deposited on (0001) sapphire substrates by radio frequency (rf) reactive magnetron sputtering at different N2/O2 ratios, has been observed at room temperature. Both the p-type conduction and ferromagnetism are originated from the substitution of O with N. At the N2/O2 ratio of 15:15, the film displays the maximum hole density and the minimum resistivity as well as the maximum Ms. The transition from n-type to p-type strongly depends on both the substitutional nitrogen on the oxygen site (NO) and oxygen vacancy (VO) concentrations. The observed ferromagnetism of p-type ZnO:N films is intrinsic and strongly related to both the NO and VO content and can be interpreted by the bound magnetic polarons (BMPs) model. •We firstly observed room temperature ferromagnetism in p-type ZnO:N films.•The observed ferromagnetism of p-type ZnO:N films is intrinsic.•The ferromagnetism strongly related to both the NO and VO concent.•The ferromagnetism of p-type ZnO:N films can be interpreted by the BMPs model.