Ferromagnetic Properties of Y-Doped AlN Nanorods

Room-temperature ferromagnetism has been observed in Y-doped AlN (AlN:Y) nanorods. Our first-principle calculations have demonstrated that the ferromagnetism in AlN:Y is from Al vacancies and that the introduction of nonmagnetic rare-earth element Y into AlN can significantly reduce the formation energy of Al vacancy which leads to high Al vacancies responsible for the observed ferromagnetism in AlN:Y nanorods. These findings illustrate an efficient way to reduce the formation energy of cation vacancy by doping nonmagnetic elements, such as Y, leading to ferromagnetism in semiconductors.