Successful synthesis of room-temperature ferromagnetic semiconductors, (Cu, Co) co-doped ZnO film is obtained by sol-gel method. It is found that the essential ingredient in achieving room-temperature ferromagnetism is Cu co-doping. By Hall-effect measurement ap-type conductivity was observed for the Cu co-doped films, which induced the room-temperature ferromagnetism.
Our first-principles calculation finds that only the Zn vacancy can induce a 1.0 μB magnetic moment in Er-doped ZnO, which comes from the unpaired 2p electrons at the ligand O atom and results in the room-temperature ferromagnetism property of ZnO.
