A Mössbauer Effect Study of the Re₂Fe₁₄B Magnets, Where RE Is Y, Pr, Nd, and Gd

Author

Fernande Grandjean, Missouri University of Science and TechnologyFollow
Gary J. Long, Missouri University of Science and TechnologyFollow
Oran Allan Pringle, Missouri University of Science and TechnologyFollow
Jie Fu

Abstract

The Mössbauer spectra of Pr₂Fe₁₄B and Gd₂Fe₁₄B have been measured from 85 to 295 K and fit with a second order approximation in which the angle, φ, between the principal axis of the electric field gradient and the easy-axis of magnetization has been fixed by the positions of the near-neighbor rare-earth atoms. The coordination environment for each of the six iron sites in these materials has been determined from the Wigner-Seitz cell and used in the spectral analysis. The hyperfine parameters resulting from the above fit are in agreement with the structural and electronic properties of these compounds and also agree well with those determined in our earlier studies of Nd₂Fe₁₄B and Y₂Fe₁₄B. The magnetic hyperfine fields for the different sites are similar in the Y, Pr, and Nd compounds but are, as expected, higher in the Gd compound because of the much higher spin-multiplicity associated with Gd. The hyperfine fields on the 8 j₁ and 4 c sites, which have the most rare-earth near-neighbors show, as expected, the largest variation with rare-earth atom. The quadrupole interactions are constant with temperature and the absolute value of the quadrupole interactions on the 8 j₂ and 4 e site are found to be the largest, as is consistent with the highly distorted environment of these sites With the possible exception of the 4 c site, the quadrupole interaction shows little variation with rare-earth atom. The isomer shift for each site in each compound varies linearly with temperature, as expected, for the second-order Doppler shift and gives effective Mössbauer masses between 62 and 67 g/mole. The weighted average isomer shift is similar in each of these compounds, but the isomer shifts associated with some of the specific sites in Gd₂Fe₁₄B are rather different than in the Y, Pr, and Nd compounds.

Recommended Citation

F. Grandjean et al., "A Mössbauer Effect Study of the Re₂Fe₁₄B Magnets, Where RE Is Y, Pr, Nd, and Gd," Hyperfine Interactions, vol. 62, no. 2016-01-02, pp. 131 - 146, Springer Verlag, Aug 1990.

The definitive version is available at https://doi.org/10.1007/BF02407668

Department(s)

Chemistry

Second Department

Physics

International Standard Serial Number (ISSN)

0304-3834

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1990 Springer Verlag, All rights reserved.

Publication Date

01 Aug 1990