We were interested in characterizing films of cubic gamma"-FeN not only by X-ray diffraction, but also by scanning electron microscopy and transmission electron microscopy. Samples were fabricated by dc magnetron sputtering of an iron target in N-2 atmosphere at high pressure. The Xray diffraction technique indicated that films were composed of a single phase, i.e. the gamma"-FeN phase. Scanning electron microscopy and transmission electron microscopy showed the presence of a strong < 111 > texture in the coatings. Film microstructure consisted of triangular cross-section rods perpendicular to the substrate. These rods contain 1111 twin defects. We also frequently observed supplementary diffraction spots on electron diffraction patterns of some rods. The intensity of these spots is much less than those of the gamma"-FeN phase. These weak spots also lie at half the distance between two consecutive spots of the gamma"-FeN phase. These two facts suggest that these additional spots correspond to a superstructure of the gamma"-FeN. This new phase is face-centered cubic and its lattice parameter is twice the one of gamma"-FeN, i.e. a = 0.864 nm. Darkfield transmission electron microscopy experiments performed with both fundamental and superstructure spots indicate that the new phase is located on the surface of the rods and form nanodomains. (c) 2005 Elsevier B.V. All rights reserved.