FeCr2S4 in magnetic fields: possible evidence for a multiferroic ground state.
Sci Rep
; 4: 6079, 2014 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-25123960
ABSTRACT
We report on neutron diffraction, thermal expansion, magnetostriction, dielectric, and specific heat measurements on polycrystalline FeCr2S4 in external magnetic fields. The ferrimagnetic ordering temperatures TC ≈ 170â
K and the transition at TOO ≈ 10â
K, which has been associated with orbital ordering, are only weakly shifted in magnetic fields up to 9â
T. The cubic lattice parameter is found to decrease when entering the state below TOO. The magnetic moments of the Cr- and Fe-ions are reduced from the spin-only values throughout the magnetically ordered regime, but approach the spin-only values for fields >5.5â
T. Thermal expansion in magnetic fields and magnetostriction experiments indicate a contraction of the sample below about 60â
K. Below TOO this contraction is followed by a moderate expansion of the sample for fields larger than ~4.5â
T. The transition at TOO is accompanied by an anomaly in the dielectric constant. The dielectric constant depends on both the strength and orientation of the external magnetic field with respect to the applied electric field for T < TOO. A linear correlation of the magnetic-field-induced change of the dielectric constant and the magnetic-field dependent magnetization is observed. This behaviour is consistent with the existence of a ferroelectric polarization and a multiferroic ground state below 10â
K.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Austrália