The mechanism of photo-regulated magnetization in copper oxide films on Pt substrate

Abstract We demonstrate that the copper oxide films deposited on Pt/Ti/SiO2/Si substrates exhibit the room temperature ferromagnetism. The ferromagnetism would be mainly induced by the indirect double exchange at interface between CuO and Cu2O. The ferromagnetism (mainly saturation magnetization) could be enhanced at room temperature by visible light. The built-in electric field has a great effect on the photo-regulated magnetization. We suggested that the enhanced indirect double exchange affect the changed ferromagnetism of copper oxide film, which is associated with the valence transition of Cu ion in a local area.