H mediated room temperature ferromagnetism in Zn0.98Cu0.02O

Zn0.98Cu0.02O powders have been synthesized by microemulsion method. The room temperature ferromagnetism was significantly suppressed, compared with the ZnO powders prepared by the same method. Enhanced room temperature ferromagnetism has been obtained after annealing in H2 atmosphere at 500 °C for 2 h. The structural characterizations have confirmed the incorporation of the interstitial H and the suppression of the O vacancies. The possibility of the O vacancy mediated room temperature ferromagnetism has been excluded. Our results clearly demonstrated that the observed ferromagnetism originates from the neighboring Cu ions mediated by the interstitial H ions.

► The room temperature ferromagnetism was suppressed by Cu doping in ZnO.
► Enhance room temperature ferromagnetism was observed in Zn0.98Cu0.02O after annealing in H2.
► The ferromagnetism originates from the neighboring Cu ions mediated by the interstitial H ions.