Hole-mediated ferromagnetism in a high-magnetic moment material, Gd-doped GaN

As an exotic material in spintronics, Gd-doped GaN is known as a room temperature ferromagnetic material that possesses a large magnetic moment (4000 μ _B per Gd ion). This paper theoretically proposes that the large magnetic moment and room temperature ferromagnetism observed in Gd-doped GaN is caused by N 2p holes based on the assumption that Ga-vacancies result from the introduction of Gd ions. This causes that the too large magnetic moment is estimated for Gd ions if only Gd ions contributed the magnetic moment. (paper)