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Crystallographic and Magnetic Structures of Fe7Se8
New Phys.: Sae Mulli 2019; 69: 221~226
Published online March 29, 2019;
© 2019 New Physics: Sae Mulli.

Eng Chan KIM*

Department of Physics, Yeungnam University, Gyeongsan 38541, Korea
Correspondence to:
Received December 3, 2018; Revised January 3, 2019; Accepted January 16, 2019.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Mössbauer spectra of ferrimagnetic Fe7Se8 prepared with enriched 57Fe have been taken at temperatures
from 4 K to 450 K. Three sets of six-line hyperfine patterns were obtained and assigned to three magnetically nonequivalent sites of a superstructure of the crystal. The results obtained
in the low-temperature region are shown to be consistent with the “3c” super structure model. An abrupt change in the quadrupole shifts near 130 K for Fe7Se8 suggests that the spin-rotation transition
proceeds abruptly. The isomer shifts for Fe7Se8 indicate a ferrous character for the iron atoms at all three sites. Similarly, some bumps, which are related to the spin rotation, in the temperature
dependence of magnetic hyperfine fields for Fe7Se8. Fe7Se8 are found to have a orthohexagonal crystal structure.
PACS numbers: 76.80.+y
Keywords: Spin rotation transition, Ferrimagnetism, Mössbauer spectroscopy, Fe7Se8

May 2019, 69 (5)
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