Abstract
Fe-enriched samples were synthesized in a laser-heated diamond anvil cell at a pressure of about 15 GPa and a temperature of about 2000 K. Nuclear forward scattering (NFS) spectra were collected in the range 0–40 GPa and were combined with first-principles calculations to provide insights into the magnetic properties of . NFS spectra show that strong magnetic interactions persist up to 40 GPa and that they are generated by a single magnetic contribution. The hyperfine magnetic field and quadrupole splitting (QS) are in the ranges 51–53 T and 0.40–1.2 mm , respectively. The QS shows an intriguing evolution with pressure, with a fast increase from 0.4 to 1.0 mm between 0 and 10 GPa and a slow increase up to 1.2 mm in the range 10–40 GPa. First-principles calculations suggest an antiferromagnetic ordering for the three sites, and similar magnetic moments in the range 3.6–3.8 μFe. These values, typical of strongly correlated Fe magnetic systems, are in agreement with the experimental estimated average moment of 3.8 μFe. The single contribution to the NFS spectrum and the similar calculated magnetic moments suggest that the iron atoms at the three crystallographic sites have similar electronic arrangements.
- Received 3 November 2013
- Revised 25 June 2014
DOI:https://doi.org/10.1103/PhysRevB.90.024430
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