Self-diffusion of iron in amorphous iron nitride

Abstract

The measurement of self-diffusion of iron in amorphous ${\mathrm{FeN}}_{0.7}$ using secondary-ion mass spectroscopy is reported. Diffusion broadening of tracer layers of ${}^{57}{\mathrm{FeN}}_{0.7}$ was observed after isothermal vacuum annealing of the films at different temperatures. Strong structural relaxation effects on diffusion coefficient were observed below crystallization temperature of the amorphous phase. In the well-relaxed state, the values of preexponential factor ${D}_{0}$ and activation energy q are given by $\mathrm{ln}{D}_{0}=\ensuremath{-}16.6\ifmmode\pm\else\textpm\fi{}2{\mathrm{m}}^{2}/\mathrm{s}$ and $q=1.3\ifmmode\pm\else\textpm\fi{}0.2\mathrm{eV}.$ On the basis of correlation between $\mathrm{ln}{D}_{0}$ and q, it is suggested that the mechanism of self-diffusion of iron in amorphous iron nitride is very similar to that in metallic glasses.