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Title: A Moessbauer-effect study of a series of R sub 2 Fe sub 14 C hard magnetic materials

Abstract

The {sup 57}Fe Moessbauer-effect spectra of the series of hard magnetic materials, R{sub 2}Fe{sub 14}C, where R is Nd, Gd, Tb, Dy, Ho, and Lu, have been measured at 295 K. All of these carbides exhibit uniaxial magnetic anisotropy. The spectra resemble those obtained for the related R{sub 2}Fe{sub 14}B compounds and have been fit with the model used earlier for Nd{sub 2}Fe{sub 14}B. The magnitude of the hyperfine field on each site, as a function of rare earth, parallels the Curie temperature; the maximum hyperfine fields and the maximum Curie temperature are observed for Gd{sub 2}Fe{sub 14}C. A linear correlation is observed between the hyperfine fields on the six sites in the analogous borides and carbides; however, these fields are systematically smaller in the carbides. The decrease in the tetragonal unit cell {ital c}-axis length in the carbides apparently reduces the exchange interactions between the 8{ital j} and 16{ital k} iron layers and hence reduces the moments. The isomer shift on each site decreases as the atomic number of the rare earth increases, whereas the quadrupole interactions are independent of rare earth.

Authors:
; ;  [1];  [2];  [3]
  1. Department of Chemistry, University of Missouri-Rolla, Rolla, Missouri 65401 (USA) Department of Physics, University of Missouri-Rolla, Rolla, Missouri 65401 (USA)
  2. Institut de Physique, Universite de Liege, B-4000 Sart-Tilman, (Belgium)
  3. Philips Research Laboratory, NL-5600 JA Eindhoven, (The Netherlands)
Publication Date:
OSTI Identifier:
5690224
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics; (USA)
Additional Journal Information:
Journal Volume: 69:8; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DYSPROSIUM CARBIDES; MAGNETIC PROPERTIES; GADOLINIUM CARBIDES; HOLMIUM CARBIDES; IRON CARBIDES; LUTETIUM CARBIDES; NEODYMIUM CARBIDES; TERBIUM CARBIDES; IRON 57; MEDIUM TEMPERATURE; MOESSBAUER EFFECT; CARBIDES; CARBON COMPOUNDS; DYSPROSIUM COMPOUNDS; EVEN-ODD NUCLEI; GADOLINIUM COMPOUNDS; HOLMIUM COMPOUNDS; INTERMEDIATE MASS NUCLEI; IRON COMPOUNDS; IRON ISOTOPES; ISOTOPES; LUTETIUM COMPOUNDS; NEODYMIUM COMPOUNDS; NUCLEI; PHYSICAL PROPERTIES; RARE EARTH COMPOUNDS; STABLE ISOTOPES; TERBIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; 360204* - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats

Long, G J, Pringle, O A, Marasinghe, G K, Grandjean, F, and Buschow, K H.J. A Moessbauer-effect study of a series of R sub 2 Fe sub 14 C hard magnetic materials. United States: N. p., 1991. Web. doi:10.1063/1.347763.
Long, G J, Pringle, O A, Marasinghe, G K, Grandjean, F, & Buschow, K H.J. A Moessbauer-effect study of a series of R sub 2 Fe sub 14 C hard magnetic materials. United States. doi:10.1063/1.347763.
Long, G J, Pringle, O A, Marasinghe, G K, Grandjean, F, and Buschow, K H.J. Mon . "A Moessbauer-effect study of a series of R sub 2 Fe sub 14 C hard magnetic materials". United States. doi:10.1063/1.347763.
@article{osti_5690224,
title = {A Moessbauer-effect study of a series of R sub 2 Fe sub 14 C hard magnetic materials},
author = {Long, G J and Pringle, O A and Marasinghe, G K and Grandjean, F and Buschow, K H.J.},
abstractNote = {The {sup 57}Fe Moessbauer-effect spectra of the series of hard magnetic materials, R{sub 2}Fe{sub 14}C, where R is Nd, Gd, Tb, Dy, Ho, and Lu, have been measured at 295 K. All of these carbides exhibit uniaxial magnetic anisotropy. The spectra resemble those obtained for the related R{sub 2}Fe{sub 14}B compounds and have been fit with the model used earlier for Nd{sub 2}Fe{sub 14}B. The magnitude of the hyperfine field on each site, as a function of rare earth, parallels the Curie temperature; the maximum hyperfine fields and the maximum Curie temperature are observed for Gd{sub 2}Fe{sub 14}C. A linear correlation is observed between the hyperfine fields on the six sites in the analogous borides and carbides; however, these fields are systematically smaller in the carbides. The decrease in the tetragonal unit cell {ital c}-axis length in the carbides apparently reduces the exchange interactions between the 8{ital j} and 16{ital k} iron layers and hence reduces the moments. The isomer shift on each site decreases as the atomic number of the rare earth increases, whereas the quadrupole interactions are independent of rare earth.},
doi = {10.1063/1.347763},
journal = {Journal of Applied Physics; (USA)},
issn = {0021-8979},
number = ,
volume = 69:8,
place = {United States},
year = {1991},
month = {4}
}