Journal article
The relation between local structural distortion and the low-temperature magnetic anomaly in Fe7S8
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.
Language: | English |
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Year: | 2018 |
Pages: | 425803 |
ISSN: | 1361648x and 09538984 |
Types: | Journal article |
DOI: | 10.1088/1361-648X/aadf54 |
ORCIDs: | 0000-0003-4661-6591 , 0000-0003-2825-6027 and 0000-0003-2700-2578 |