Magnetic doping and characterization of n-type GaN

n-type GaN films grown on sapphire by MOCVD were doped with Mn and Cr by solid state diffusion and characterized by various methods. Hall measurement shows that the samples still remain n-type after the diffusion. Secondary Ion Mass Spectroscopy (SIMS) results show a good diffusion of Mn and Cr inside GaN. X-ray diffraction (XRD) reveals no secondary phases in the samples. Superconducting quantum interference device (SQUID) results show that the samples are ferromagnetic up to room temperature. The possible origin of ferromagnetism is discussed. © 2005 American Institute of Physics.published_or_final_versio