Iron samples were implanted at a fluence of 1017N+ions.cm−2with an energy of 50 keV. The beam current density was varied in the range 6–60 μA.cm−2as well as the quality of the vacuum in the implantation chamber. Implantations were performed at 150°C to favour the carburization process. Carbon and oxygen contaminations were controlled using nuclear backscattering spectrometry (NBS) with α particles of 5.7 MeV and 7.5 MeV respectively or by using Auger electron spectroscopy (AES). The depth profiles of implanted nitrogen were determined by the15N(p,αγ) nuclear reaction or by AES when15N or14N ions were implanted respectively. Implantation induced chemical phases were characterized using Mössbauer spectroscopy and electron diffraction.