Ferromagnetism in Fe‐doped ZnO bulk samples with additional Cu doping

Abstract

Abstract Room‐temperature (RT) ferromagnetism (FM) has been observed in Fe‐doped ZnO bulk samples fabricated by a coprecipitation method, and the effect of additional Cu doping on magnetic properties of the samples has been investigated. The results of XRD show that all doping samples are single‐phase with a wurtzite structure. X‐ray photoelectron spectroscopy reveals that Fe is in 3+ state substituting for Zn in the sample without Cu doping, however, Fe shows a mixed oxidation state of 2+ or 3+ in the sample with additional Cu doping, where Cu is 1+ valence. Magnetic measurements indicate that additional Cu doping enhances the FM of the system, and the magnetization increases gradually with the increasing Cu content x up to 1%. The observed RT FM was attributed to the ferromagnetic coupling between Fe 3+ ions mediated by holes.