The structural and magnetic properties of siderite FeCO3 have been studied by means of neutron powder diffraction at pressures up to 7.5 GPa and first-principles theoretical calculations. The lattice compression in the rhombohedral calcite-type structure is dominated by the reduction of the Fe-O bonds, while the changes of the C-O bonds are much less pronounced. The Néel temperature of the antiferromagnetic (AFM) ground state increases substantially under pressure with a coefficient dTN/dP=1.8K/GPa, which is about 1.5 times larger in comparison with those predicted by the empirical Bloch rule. The ab initio calculations were performed in the framework of the density functional theory including Hubbard-U correction. The calculated structural parameters and Néel temperature as functions of pressure provide a reasonable agreement with the experimental results. The analysis of the density of electronic states points toward increased covalent bonding between the Fe and O atoms upon pressure, giving rise to unexpectedly large pressure coefficient of the Néel temperature and reduced ordered magnetic moments of Fe atoms.

Golosova, N., Kozlenko, D., Dubrovinsky, L., Cerantola, V., Bykov, M., Bykova, E., et al. (2017). Magnetic and structural properties of FeCO3 at high pressures. PHYSICAL REVIEW. B, 96(13) [10.1103/PhysRevB.96.134405].

Magnetic and structural properties of FeCO3 at high pressures

Cerantola V;
2017

Abstract

The structural and magnetic properties of siderite FeCO3 have been studied by means of neutron powder diffraction at pressures up to 7.5 GPa and first-principles theoretical calculations. The lattice compression in the rhombohedral calcite-type structure is dominated by the reduction of the Fe-O bonds, while the changes of the C-O bonds are much less pronounced. The Néel temperature of the antiferromagnetic (AFM) ground state increases substantially under pressure with a coefficient dTN/dP=1.8K/GPa, which is about 1.5 times larger in comparison with those predicted by the empirical Bloch rule. The ab initio calculations were performed in the framework of the density functional theory including Hubbard-U correction. The calculated structural parameters and Néel temperature as functions of pressure provide a reasonable agreement with the experimental results. The analysis of the density of electronic states points toward increased covalent bonding between the Fe and O atoms upon pressure, giving rise to unexpectedly large pressure coefficient of the Néel temperature and reduced ordered magnetic moments of Fe atoms.
Articolo in rivista - Articolo scientifico
siderite; carbonates; low temperature; high pressure; neutron diffraction
English
Golosova, N., Kozlenko, D., Dubrovinsky, L., Cerantola, V., Bykov, M., Bykova, E., et al. (2017). Magnetic and structural properties of FeCO3 at high pressures. PHYSICAL REVIEW. B, 96(13) [10.1103/PhysRevB.96.134405].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/397752
Citazioni
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 9
Social impact