The electronic structure of an interface and O-vacancy states in Fe/MgO/Fe junctions was investigated by using first-principles calculations within density functional theory. The magnetic moment of the interface Fe layer increased relative to that of the bulk. The defect states in a Fe/MgO cluster containing an O vacancy induced no significant shift in the Fermi level.

Interfacial Electronic Structure and Oxygen Vacancy states in Fe/MgO/Fe Tunneling Junctions. J.Ozeki, H.Itoh, J.Inoue: Journal of Magnetism and Magnetic Materials, 2007, 310[2], e644-5