Structure and magnetic properties of Sr2CoWO6: An ordered double perovskite containing Co2+(HS) with unquenched orbital magnetic moment

M. C. VIOLA; M. J. MARTÍNEZ-LOPE; J. A. ALONSO; J. L. MARTÍNEZ; J. M. DE PAOLI; S. PAGOLA; J. C. PEDREGOSA; M. T. FERNÁNDEZ-DÍAZ; R. E. CARBONIO

CHEMISTRY OF MATERIALS

American Chemical Society

Lugar: Washington, DC, USA; Año: 2003 vol. 15 p. 1655 - 1655

0897-4756

Sr2CoWO6 perovskite has been prepared in polycrystalline form by solid-state reaction at1150 °C. This material has been studied by high-resolution synchrotron X-ray and neutronpowder diffraction (NPD), magnetic measurements, and differential scanning calorimetry(DSC). At room temperature, the crystal structure is tetragonal, space group I4/m, with a=5.58277(1) Å and c= 7.97740(1) Å. The structure contains alternating CoO6 and WO6octahedra, tilted in anti-phase by 7.24° in the basal ab plane along the [001] direction of thepseudocubic cell. This corresponds to the a0a0c- Glazer’s notation as derived by Woodwardfor 1:1 ordering of double perovskites, consistent with space group I4/m. DSC and NPDmeasurements as a function of temperature indicate a structural transition from tetragonalto monoclinic (space group P21/n) at 260 K. At 2 K the cell parameters are a= 5.61267(8)Å, b= 5.58753(8) Å, c= 7.8994(1) Å, and beta= 90.041(3)°.