A relatively simple, and high-efficiency method is reported to synthesize AlN nanowires, using catalyst-assisted chemical vapor deposition. A thin film of 5 nm Ni layer was deposited on sapphire as catalyst. Structural property of as-grown nanowires was investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) These large scale, high quality and uniform nanowires have smooth surface with diameter of 50 nm and length of 10-30 mu m, which are hexagonal single-crystalline with c = 0.497 nm, a = 0.272 nm and grow along [100] direction. Our results provide the first direct evidence of vapor-liquid-solid growth mechanism for AlN nanowires.
