Synthesis and characterization of iron nitrides. An XRD, Mössbauer, RBS and XPS characterization

Abstract

In this work, we demonstrate the capability of a dual ion beam sputtering method to obtain iron nitride thin films, FeN x , in a wide composition range (0.1 < x < 0.5) and structures (α , γ , ε, ζ , γ and γ ) by controlling the deposition conditions (i.e. deposition rate, flux and energy of the assisting nitrogen ions and substrate temperature). The average composition of the films has been determined by resonant RBS to enhance the nitrogen signal, whereas the structural characterization and the phase identification have been carried out by X-ray diffraction (XRD) and Mössbauer spectroscopy. We present a thorough and complementary analysis of the XRD and Mössbauer data as a function of the composition of the film for all the iron nitride phases. Furthermore, it is shown that the iron Auger parameter (AP) increases up to 0.8 eV with respect to that for pure α-Fe when the nitrogen concentration increases up to 46 at.% (i.e. γ and γ phases) so that it might serve to analyze samples of unknown composition.

Mössbauer study of iron nitride films produced by pulsed laser deposition

“…Iron nitrides with low nitrogen contents have been extensively studied, whereas iron nitrides with high nitrogen contents have not been well investigated. FeN has been R. Usui (B) · Y. Yamada Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan e-mail: jb110629@ed.kagu.tus.ac.jp reported to have two phases, γ "-FeN (ZnS structure) and γ "'-FeN (NaCl structure), which generally form simultaneously so that it is difficult to produce a single phase [4][5][6][7][8]. In this study, we report the production of iron nitride films using PLD.…”

“…Iron nitride films or particles have been prepared by various methods [4][5][6][7][8][9]. Iron nitrides with low nitrogen contents have been extensively studied, whereas iron nitrides with high nitrogen contents have not been well investigated.…”

FeN nanoparticles confined in carbon nanotubes for CO hydrogenation

“…7 A cubic FeN phase with a higher nitrogen content of 50 at% N was theoretically predicted 8,9 and recently synthesized in the form of a thin film by reactive magnetron sputtering, 10 molecular beam epitaxial growth 11 and ion bombardment. 12 However, almost nothing is known about the stability and catalytic activity of this cubic FeN in CO hydrogenation, which contains more nitrogen than the above-mentioned nitrides.…”

Enhancement of Light Olefins Selectivity Over N-Doped Fischer-Tropsch Synthesis Catalyst Supported on Activated Carbon Pretreated with KMnO4

“…On the basis of the Fe2p spectra shift to higher binding energies (Figure 2c), it can be inferred that the interaction between Fe and N is formed on the catalysts when using ammonium iron citrate as precursor. It means that in the crystal lattice of iron oxides, N atoms partially replace O atoms and get into the Fe lattice to form iron nitrides [26,27]. In brief, nitrogen atoms are not doped into carbon networks but iron lattice.…”