SUBTLE INTERPLAY BETWEEN HYDROGEN AND MAGNETISM IN Co DOPED ZnO

Abstract

The effects of hydrogen, either interstitial (HI) or substitutional (Ho), on magnetic properties of Co doped ZnO (ZnO:Co) have been systematically investigated using first-principles density functional calculations. The study discovers the correlation between the distribution of Co ions and the hydrogen point defect and magnetism. It is found that Co ions and hydrogen have a strong tendency toward aggregation and hydrogen mainly contributes to the room temperature ferromagnetism observed experimentally in ZnO:Co . Furthermore, in ZnO:Co , the formation of Ho with four-fold hydrogenic bonds is favored over HI by 0.4 eV.