Ferromagnetism in Cu-doped MgO: Density-functional calculations

•Cu monodoped in MgO prefers a ferromagnetic ground state and half metallic behavior.•The magnetic moment mainly comes from the spin polarized Cu 3d and O 2p electrons.•The ferromagnetism can be explained in terms of p–d hybridization mechanism.•Room temperature ferromagnetism (FM) can be expected.•Mg vacancy profits half metallic FM stability while O vacancy destroys FM stability.

Using first-principles calculations based on density functional theory, we investigated systematically the electronic structures and magnetic properties of Cu monodoping and (Cu, Mg or O vacancy) codoping in MgO. The results indicate that monodoping of Cu in MgO prefers a ferromagnetic ground state and a half metallic behavior with a magnetic moment of 1 μB per Cu dopant. The magnetic moment mainly comes from the spin polarized Cu 3d and O 2p electrons which can be explained in terms of p–d hybridization mechanism and room temperature ferromagnetism can be expected. In addition, it was also found that Mg vacancy is propitious to the half metallic ferromagnetism stability while O vacancy destroys ferromagnetic ground state in Cu doped MgO. These results suggest that the Cu-doped MgO is a promising candidate material for room temperature spintronics applications.