Mössbauer study of iron nitride films produced by pulsed laser deposition

Iron nitride films were produced by pulsed laser deposition of Fe onto an Al substrate in an N2 atmosphere and their Mössbauer spectra and powder X-ray diffraction patterns were measured. The nitrogen content of the iron nitride films varied depending on the N2 pressure. Under high N2 pressures, γ"-FeN (ZnS structure) and γ'"-FeN (NaCl structure) were obtained. The yields of these two phases could be controlled by varying the Al substrate temperature. γ"-FeN and γ'"-FeN were found to be paramagnetic and antiferromagnetic, respectively, at 5 K.