The microstructure, stoichiometric ratio and room temperature ferromagnetic properties of V-doped ZnO films deposited at different substrate temperatures

The vanadium doped ZnO (ZnO:V) films were deposited on glass substrate by radio frequency (r.f.) magnetron sputtering at different substrate temperatures. The results show that the substrate temperature significantly influences the morphology, crystallinity, stoichiometric ratio and concentration of oxygen in different chemical states of the ZnO:V films. The film deposited at 450 °C possesses good crystallinity, strong (002) orientation and near-regular hexagonal prismatic particles. The VSM results demonstrate that all the ZnO:V films exhibit room temperature ferromagnetic behavior and it is also the ZnO:V film deposited at 450 °C that shows the highest saturation moment (Ms) of about 46.12 emu/cm 3 . The XPS results indicate that V 4+ and V 5+ ions coexist in the ZnO:V films and are mainly responsible for the room temperature ferromagnetic behavior.