by E. Andrzejewska, R. Gonzalez-Arrabal, D. Borsa and D. O. Boerma
Abstract:
Most of the Fe–nitride phases have been studied in much detail. Nevertheless, there is still some uncertainty regarding the characterisation of the FeNy compounds with ytextgreater0.5. On the basis of theoretical calculations, two FeN compounds are predicted with different phases: γ″-FeN and the γ‴-FeN. However, up to now there is no conclusive experimental evidence for the existence of these two phases. In the present work we present strong evidence that FeNy (ytextgreater0.5) contains only one pure phase, the γ″-FeN, with some vacancies. We developed two new methods to grow FeNy (ytextgreater0.5) phases: by evaporating Fe in the presence of a flow of atomic nitrogen and by post-nitriding under certain condition a thin epitaxial γ′-Fe4N sample. The stoichiometry of the samples was determined from resonant RBS with an accuracy of better than 1%. The samples were investigated by room temperature conversion electron Mössbauer spectroscopy (CEMS). For samples grown at a temperature lower than 300°C CEMS spectra can be fitted by a singlet line corresponding to a phase with 4-fold-symmetry, plus a quadrupole doublet that can be explained by symmetry breaking due to the presence of vacancies. We will show that the number of N vacancies (with respect to the FeN stoichiometry) determined by resonant RBS and the relative fraction of the singlet line in the CEMS-spectra agree well with this interpretation of the spectra, if the γ″-FeN structure is assumed. The interpretation is supported by theoretical band structure calculations that were performed.
Reference:
E. Andrzejewska, R. Gonzalez-Arrabal, D. Borsa and D. O. Boerma, “Study of the phases of iron–nitride with a stoichiometry near to FeN”, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, vol. 249, no. 1, pp. 838–842.
Bibtex Entry:
@article{andrzejewska_study_2006,
series = {Ion {Beam} {Analysis}},
title = {Study of the phases of iron–nitride with a stoichiometry near to {FeN}},
volume = {249},
issn = {0168-583X},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X06004186},
doi = {10.1016/j.nimb.2006.03.150},
abstract = {Most of the Fe–nitride phases have been studied in much detail. Nevertheless, there is still some uncertainty regarding the characterisation of the FeNy compounds with y{textgreater}0.5. On the basis of theoretical calculations, two FeN compounds are predicted with different phases: γ″-FeN and the γ‴-FeN. However, up to now there is no conclusive experimental evidence for the existence of these two phases. In the present work we present strong evidence that FeNy (y{textgreater}0.5) contains only one pure phase, the γ″-FeN, with some vacancies. We developed two new methods to grow FeNy (y{textgreater}0.5) phases: by evaporating Fe in the presence of a flow of atomic nitrogen and by post-nitriding under certain condition a thin epitaxial γ′-Fe4N sample. The stoichiometry of the samples was determined from resonant RBS with an accuracy of better than 1%. The samples were investigated by room temperature conversion electron Mössbauer spectroscopy (CEMS). For samples grown at a temperature lower than 300°C CEMS spectra can be fitted by a singlet line corresponding to a phase with 4-fold-symmetry, plus a quadrupole doublet that can be explained by symmetry breaking due to the presence of vacancies. We will show that the number of N vacancies (with respect to the FeN stoichiometry) determined by resonant RBS and the relative fraction of the singlet line in the CEMS-spectra agree well with this interpretation of the spectra, if the γ″-FeN structure is assumed. The interpretation is supported by theoretical band structure calculations that were performed.},
number = {1},
urldate = {2017-07-21},
journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
author = {Andrzejewska, E. and Gonzalez-Arrabal, R. and Borsa, D. and Boerma, D. O.},
month = aug,
year = {2006},
keywords = {CEMS, FeN growth, MBE, Phase identification, Resonant-RBS},
pages = {838--842},
file = {ScienceDirect Snapshot:E:\cmam_papers\files\498\S0168583X06004186.html:text/html;ScienceDirect Snapshot:E:\Usuarios\Administrator\Zotero\storage\YPXKHLFI\S0168583X06004186.html:text/html},
}