The relation between local structural distortion and the low-temperature magnetic anomaly in Fe7S8

Research output: Contribution to journalJournal article – Annual report year: 2018Researchpeer-review


  • Author: Koulialias, D.

    Swiss Federal Institute of Technology Zurich

  • Author: Canévet, E.

    Department of Physics, Technical University of Denmark, Fysikvej, DK-2800, Kgs. Lyngby, Denmark

  • Author: Charilaou, M.

    Swiss Federal Institute of Technology Zurich

  • Author: Weidler, P.G.

    Karlsruhe Institute of Technology

  • Author: Löffler, J. F.

    Swiss Federal Institute of Technology Zurich

  • Author: Gehring, A. U.

    Swiss Federal Institute of Technology Zurich

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Structural defects on an atomic level can crucially impact the magnetic properties of a material. We study this phenomenon by means of magnetometry and powder neutron diffraction on a stoichiometric, monoclinic pyrrhotite (Fe7S8), which is a classic omission structure with a magnetic anomaly at about 30 K. The initial structural distortion of the pyrrhotite at 300 K caused by the vacancy arrangement decreases upon cooling, and simultaneous to the magnetic anomaly the anisotropic contraction of the unit cell homogenizes the covalency of the Fe-Fe bonds with lengths less than 3.0 Å and the Fe-S-Fe bond angles. These changes on the atomic level affect the spin-orbit coupling and the super-exchange interactions in Fe7S8, and trigger the low-temperature magnetic anomaly within a crystallographically stable system.

Original languageEnglish
Article number425803
JournalJournal of Physics Condensed Matter
Issue number42
Number of pages8
Publication statusPublished - 2018
CitationsWeb of Science® Times Cited: No match on DOI

    Research areas

  • Exchange interactions, Magnetic anisotropy, Monoclinic pyrrhotite, Spin orbit coupling, Vacancies

ID: 161972352