Magnetodielectric Effect in Crystals of the Noncentrosymmetric CaOFeS at Low Temperature

C. Delacotte (1, 2) , O. Perez (2) , A. Pautrat (2) , David Berthebaud (2) , S. Hébert (2) , E. Suard (3) , D. Pelloquin (2) , A. Maignan (2)

1 LaMIPS - Laboratoire de Microélectronique et de Physique des Semiconducteurs
2 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
3 ILL - Institut Laue-Langevin

Single crystals of the stoichiometric iron calcium oxysulfide CaOFeS have been grown by a solid-state reaction. Structural analysis of CaOFeS at room temperature by combining single-crystal X-ray diffraction data and transmission electron microscopy leads to a stoichiometric hexagonal noncentrosymmetric P63mc layered structure isostructural to CaOZnS. It is built from alternating layers made of FeOS3 tetrahedra sharing sulfur apexes and stacked with Ca2+ planes. All Fe-O bonds are parallel to the stacking axis; this breaks the centrosymmetry, leading to a polar structure. The dielectric measurements reveal the existence of a magnetodielectric effect near 33 K in good agreement with the Neel temperature, as evidenced near 35 K by specific heat measurements reported by a different group. (Figure Presented). © 2015 American Chemical Society.

Keywords: Phase transitions; Space group; Physical and chemical processes; Crystal structure; Insulators

Domains: Chemical Sciences; Chemical Sciences; Cristallography; Chemical Sciences; Material chemistry; Chemical Sciences; Theoretical and/or physical chemistry

C. Delacotte, O. Perez, A. Pautrat, David Berthebaud, S. Hébert, et al.. Magnetodielectric Effect in Crystals of the Noncentrosymmetric CaOFeS at Low Temperature. Inorganic Chemistry, 2015, 54 (13), pp.6560-6565. ⟨10.1021/acs.inorgchem.5b00879⟩. ⟨hal-02184139⟩