Local effects of interstitial versus substitutional atoms in Y{sub 2}Fe{sub 17{minus}x}M{sub x}A{sub y} compounds, with M=Al or Si and A=C or N
- National Institute of Materials Physics, P.O. Box MG-07, 76900-Bucharest (Romania)
Interstitial Y{sub 2}Fe{sub 17{minus}x}M{sub x}C{sub y} compounds, with M=Al or Si and x{le}2, y{le}1, were investigated by {sup 57}Fe M{umlt o}ssbauer spectroscopy at room temperature. In the analysis of the spectra, the preferential occupation by Al or Si of the Fe (12k) sites in the hexagonal R{sub 2}Fe{sub 17} phase was taken into account. The hyperfine parameters variations are discussed on the grounds of local crystallographic details at the inequivalent iron sites, altered by the composition modifications. The low values of the isomer shifts and quadrupole interactions suggest small electronic charge redistribution in Y{sub 2}Fe{sub 17{minus}x}M{sub x}A{sub y} as compared to Y{sub 2}Fe{sub 17}. However, the isomer shift variations upon Wigner{endash}Seitz cell volume changes evidence for screening and electron transfer effects. In order to provide a more consistent picture of the local effects of interstitial versus substitutional atoms in R{sub 2}(Fe,M){sub 17}A{sub y} compounds, the discussion of the present results is extended to {sup 57}Fe M{umlt o}ssbauer data obtained on the parent compounds and their nitrides. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 550455
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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