Aligned Fe-carbon composite nonofibers (Fe-CNFs) grew on graphite substrates bombarded by Ar+ ions at an oblique incident angle with a simultaneous Fe supply at room temperature. Morphology alteration and crystallinity variation of Fe-CNFs were achieved by adjusting the supply rate of Fe atoms. The effects of different Fe concentrations on the morphological and crystalline structures of Fe-CNFs were discussed in detail. The higher the Fe supply rates, the higher the Fe concentration in Fe-CNFs. Higher Fe concentration in Fe-CNFs favors the graphitization of carbon materials, but destroys the directivity of Fe-CNFs pointing to ion beam incident direction. The magnetic properties of Fe-CNFs with different Fe contents were also analyzed in detail. (C) 2010 Elsevier B.V. All rights reserved.