The single-phase gamma'-Fe4N nanocrystal magnetic films with grain size of d=40-60 nm were synthesized on single crystal NaCl (100) substrate by DC magnetron sputtering at 150 degrees C. The structure, morphology of the single-phase gamma'-Fe4N films were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and the magnetic properties of samples prepared at different substrate temperatures were investigated by superconducting quantum interference device (SQUID). It is shown that substrate temperature has a significant influence on the crystalline structure and magnetic properties for Fe-N films. As substrate temperature was increased, the saturation magnetization for the deposited films increased, but the coercivity reduced. (c) 2006 Elsevier B.V. All rights reserved.