An Iron-57 and Tin-119 Mössbauer Spectral Study of NdMn₆₋ₓFeₓSn₆

Author

Fernande Grandjean, Missouri University of Science and TechnologyFollow
Gary J. Long, Missouri University of Science and TechnologyFollow
Bernard M. Mahieu
Jing Zhi Han
William Joseph James, Missouri University of Science and TechnologyFollow

Abstract

The iron-57 Mössbauer spectra of the NdMn_6-xFe_xSn₆ compounds with x ≤ 0.5, 1.0, 1.5 and 2.0 have been obtained at 4.2, 78 and 295 K, and the tin-119 Mössbauer spectra of the NdMn_6-xFe_xSn₆ compounds with x ≤ 0.0, 0.5, 1.0, 1.5 and 2.0 have been obtained between 85 and 370 K. A successful and rational analysis of the spectra is based upon a Wigner-Seitz cell analysis of the HoFe₆Sn₆-structure with the Immm space group for NdMn₆Sn₆ and of the TbFe₆Sn₆- structure with the Cmcm space group for the NdMn_6-xFe_xSn₆ compounds with x ≤ 0.5, 1.0, 1.5 and 2.0. Both the iron-57 and the tin-119 spectra reveal that the spin reorientation exhibited by these compounds at low temperature is extremely sensitive to the cooling rate of the samples. Specifically, samples that are slowly cooled from 295 to 78 K retain their 295 K magnetic structure and do not exhibit a spin reorientation. In contrast, samples that are quenched from 295 to 78 K and then further cooled to 4.2 K exhibit a spin reorientation. The ca 15 T iron-57 hyperfine fields observed at 4.2 K are unusually small, whereas the ca 25 T tin-119 transferred hyperfine fields observed at 85 K are unusually large. These latter large fields, as well as the improvement in Curie temperature and magnetization with increasing iron content in the NdMn_6-xFe_xSn₆ compounds, are discussed in terms of earlier electronic structure calculations.

Recommended Citation

F. Grandjean et al., "An Iron-57 and Tin-119 Mössbauer Spectral Study of NdMn₆₋ₓFeₓSn₆," Journal of Physics: Condensed Matter, vol. 17, no. 29, pp. 4665 - 4686, Institute of Physics (IOP): Hybrid Open Access, Jul 2005.

The definitive version is available at https://doi.org/10.1088/0953-8984/17/29/009

Department(s)

Chemistry

Keywords and Phrases

Crystal Structure; Crystallization; Electronic Structure; Magnetization; Mössbauer Spectroscopy; Neodymium Compounds; Rare Earth Elements; Tin; Electronic Structure Calculations; Hyperfine Fields; Rational Analysis; Spin Reorientation; Iron

International Standard Serial Number (ISSN)

0953-8984

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 Institute of Physics (IOP): Hybrid Open Access, All rights reserved.

Publication Date

01 Jul 2005