Room-temperature ferromagnetic behavior of cobalt-doped AlN nanorod arrays

Flower-shaped Co-doped AlN nanorod arrays have been synthesized by a direct arc discharge method on an interface at high temperature. The diameter of the nanorods varies between 40 and 120 nm, and the length is in the order of several microns. High-resolution transmission electron microscopy observation indicates that Co-doped single-crystalline h-AlN nanorods grow along the direction. As-prepared AlN nanorods exhibit ferromagnetic behavior at temperatures of 300 K and 500 K.