K-edge X-ray absorption spectra of iron nitrides in FexN/Ag nanocomposites

The phases of iron nitride nanograins dispersed in a silver matrix were determined by Fe-K edge X-ray absorption near edge structure (XANES) method, which overcame difficulties caused by the ultrafine grain size and the shielding effect of the matrix. The two phases of γ'-Fe 4 N and e-Fe 2-4 N were clearly distinguished by comparing their XANES spectra with those of reference materials well characterized by XRD.