On the new ferrimagnetic Sr3Fe2UO9 double perovskite with TC above room temperature: a neutron diffraction study

R. M. PINACCA; M.C. VIOLA; J.A. ALONSO; J.C. PEDREGOSA; R.E. CARBONIO

Royal Society of Chemistry

Lugar: Cambridge, Inglaterra; Año: 2005 vol. 43 p. 4648 - 4648

p style="TEXT-ALIGN: justify; LINE-HEIGHT: 200%; MARGIN: 0cm 0cm 0pt; TEXT-AUTOSPACE: ; mso-layout-grid-align: none" class="MsoNormal">Sr3Fe2UO9 double perovskite has been prepared in polycrystalline form by a solid state reaction, in air. This material has been studied by X-ray diffraction (XRD), neutron powder diffraction (NPD) and magnetic measurements. At room temperature, the crystal structure is tetragonal, space group I4/m, with a = b = 5.6994(5) Å, c = 8.039(1) Å. Its crystallographic formula can be rewritten as Sr2Fe(Fe1/3U2/3)O6, according to the usual nomenclature for double perovskites A2B'B''O6. The structure contains alternating FeO6 and (Fe,U)O6 octahedra, almost fully ordered, tilted in antiphase by 7.6o in the basal ab plane. Magnetic measurements indicate strong ferrim