Ferromagnetic GaMnN nanowires with T-c above room temperature

We report a new method for large-scale production of GaMnN nanowires, by annealing manganese-gallium oxide nanowires in flowing ammonia at high temperature. Microstructure analysis indicates that the GaMnN nanowires have wurtzite GaN structure without Mn precipitates or Mn-related second phases. Magnetism evolution due to nitrogen doping in manganese-gallium oxide nanowires was evaluated by magnetic measurements. Magnetic measurements reveal that the magnetism is related to the change of Mn and N concentration in the sample, and the higher concentration of Mn and N leads to enhanced ferromagnetism. Ferromagnetic ordering exists in the GaMnN nanowires, whose Curie temperature is above room temperature. (c) 2005 Elsevier B.V. All rights reserved.Physics, Condensed MatterSCI(E)EI5ARTICLE1-416-2436