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

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 singlephase with a wurtzite structure. X-ray photoelectron spectroscopy reveals that Fe is in 3þ state substituting for Zn in the sample without Cu doping, however, Fe shows a mixed oxidation state of 2þ or 3þ in the sample with additional Cu doping, where Cu is 1þ 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 3þ ions mediated by holes.

Local Structure of Fe Impurity Atoms in ZnO: Bulk versus Surface

“…The calculations therefore suggest that Fe 3+ is uniformly distributed on the surface of ZnO (this is attractive for catalysis because the entire surface area is available), and ferromagnetism is not possible for isovalent substitution of Zn by Fe atoms. In fact, the latter point may help explain some recent experimental findings in which it is proposed that codoping with iron and copper is essential to the realization of ferromagnetism. ,, While it has been shown that ferromagnetic ordering is possible for some structural defects (namely S + I and 2 S + V Zn ), we have determined that these structures are not energetically favorable.…”

“…In fact, the latter point may help explain some recent experimental findings in which it is proposed that codoping with iron and copper is essential to the realization of ferromagnetism. 16,49,50 While it has been shown that ferromagnetic ordering is possible for some structural defects (namely S + I and 2S + V Zn ), we have determined that these structures are not energetically favorable.…”

Enhancing the Antibacterial Efficiency of ZnO Nanopowders Synthesized by Combustion Method Through Ag + Fe Co-doping

“…The two peaks at 1025.5 and 1046.6 eV correspond to binding energies of Zn 2p 3/2 and Zn 2p 1/2 , respectively, indicating that Zn is present in the form of Zn 2? [23]. In Fe 2? and Fe 3? ions are in close proximity to *710 eV for the BE of Fe 2p 3/2 which specify Gaussian fitting results [24].…”