Oxygen vacancy induced ferromagnetism in Cu-doped ZnO

Cu-doped ZnO was synthesized by hydrothermal method in a pulsed magnetic field. X-ray diffraction reveals the hexagonal wurtzite structure as with pure ZnO. The application of pulsed magnetic field increases the oxygen vacancy content and doping level of Cu2+ analyzed by Raman spectra and X-ray photoelectron spectroscopy. The origin of ferromagnetism is attributed to the oxygen vacancies induced Cu2+ ferromagnetic coupling.