Temperature independence of the dielectric constant in the antiferromagnetic iron intergrowth: Sr4Fe2.5O7.25(SO4)0.5. (April 2019)

• Record Type: Journal Article
• Authors: Gonano, B.; Veillon, F.; Bréard, Y.; Pelloquin, D.; Caignaert, V.; Pérez, O.; Pautrat, A.; Boullay, P.; Le Breton, J.M.; Suard, E.
• Is Part Of: Journal of physics and chemistry of solids. Volume 127(2019)
• Page Start: 88
• Page End: 93
• Publication Date: 2019-04
• Subjects: Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2018.12.009
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The magnetic structure of the anisotropic compound Sr4 Fe2.5 O7.25 (SO4 )0.5 has been determined by means of neutron diffraction and Mossbauer spectroscopy. Spins are lying in the basal plan within an antiferromagnetic G type structure. Depending on which species (O 2- or SO4 2- ) is surrounding iron atoms, latter exhibit 15% of difference on their magnetic moment at 5 k. This is in agreement with the quantitative representation of the different magnetic contributions of the Mossbauer spectrum. The compound appears to be a good dielectric, without any transition between 5 K and 400 K and a dielectric constant which is mostly temperature independent. A significate sensitivity of εr to an external applied magnetic field is finally detected. Graphical abstract: Image 1 Highlights: The antiferromagnetic structure of Sr4 Fe2.5 O7.25 (SO4 )0.5 is determined by means of neutrons diffractions at various temperature. Iron magnetic moments are sensitive to their surrounding anionic species (oxygen or sulfate). A dielectric constant which is mostly temperature independent. A significate sensitivity of εr to an external applied magnetic field is finally detected.