Compositional and magnetic properties of iron nitride thin films

Abstract

The compositional and magnetic properties of iron-nitride thin films deposited by de reactive magnetron sputtering under various nitrogen partial pressure conditions have been investigated by x-ray diffraction, Mossbauer and Auger electron spectroscopy as wen as magnetic measurements. The x-ray diffraction patterns indicate a mixed phase composition. 57Fe Mossbauer spectroscopy shows that part of the nitrogen atoms are randomly distributed on interstitial sites with the formation of nonstoichiometric compounds. The excessive width of the Mossbauer lines indicates the degree of disorder of the different iron nitride precipitates. The nitrogen concentration as a function of depth is obtained by sputter-etched Auger electron spectroscopy. Furthermore, the ferromagnetic films show moderate saturation magnetization and coercivities at room temperature as compared with pure iron thin films.