A first principle study on the magnetic properties of Cu2O surfaces

Abstract Spin-polarized density functional theory calculations were performed to investigate the magnetism of bulk and Cu 2 O surfaces. It is found that bulk Cu 2 O, Cu/O-terminated Cu 2 O(111) and (110) surfaces have no magnetic moment, while, the O-terminated Cu 2 O(100) and polar O-terminated Cu 2 O(111) surfaces have magnetism. For low index surfaces with cation and anion vacancy, we only found that the Cu vacancy on the Cu 2 O(110) Cu/O-terminated surface can induce magnetism. For atomic and molecular oxygen adsorption on the low index surfaces, we found that atomic and molecular oxygen adsorption on the Cu-terminated Cu 2 O(110) surface is much stronger than on the Cu/O-terminated Cu 2 O(111) and Cu-terminated Cu 2 O(100) surfaces. More interesting, O and O 2 adsorption on the surface of Cu/O terminated Cu 2 O(111) and O 2 adsorption on the Cu-terminated Cu 2 O(110) surface can induce weak ferromagnetism. In addition, we analysis origin of Cu 2 O surfaces with magnetism from density of state, the surface ferromagnetism possibly due to the increased 2p–3d hybridization of surface Cu and O atoms. This is radically different from other systems previously known to exhibit point defect ferromagnetism, warranting a closer look at the phenomenon.