Ferromagnetism from non-magnetic ions: Ag-doped ZnO.

To develop suitable ferromagnetic oxides with Curie temperature (T) at or above room temperature for spintronic applications, a great deal of research in doping ZnO with magnetic ions is being carried out over last decade. As the experimental results on magnetic ions doped ZnO are highly confused and controversial, we have investigated ferromagnetism in non-magnetic ion, Ag, doped ZnO. When Ag replaces Zn in ZnO, it adopts 4d configuration for Ag which has single unpaired spin and suitable exchange interaction among these spins gives rise to ferromagnetism in ZnO with above room temperature T.

Origin of ferromagnetism in Cu-doped ZnO.

It is widely reported during last decade on the observation of room temperature ferromagnetism (RTFM) in doped ZnO and other transition metal oxides. However, the origin of RTFM is not understood and highly debated. While investigating the origin of RTFM, magnetic ion doped oxides should be excluded because it is not yet settled whether RTFM is intrinsic or due to the magnetic ion cluster in ZnO.