Synthesis and magnetic study for Ga1 − xMnxN whiskers

GaN whiskers with a high content of Mn doping have been synthesized via a simple evaporation process. The microstructures and magnetic properties of the as-synthesized Ga1 − xMnxN whiskers were studied by electron microscopy and superconducting quantum interference device (SQUID). The Ga1 − xMnxN whiskers were crystalline in the hexagonal structure and had the [2 1 0] direction as the preferential growth direction. The whiskers had diameters of ≈100 nm to several hundred nm and lengths up to tens of micrometers. Magnetic measurements showed that the as-synthesized Ga1 − xMnxN whiskers contained two ferromagnetic phases with the Curie temperatures at ≈57 and 325 K. Large coercivity of ≈5000 Oe for the samples was also observed at 5 K.