La{sup 3+} doping of the Sr{sub 2}CoWO{sub 6} double perovskite: A structural and magnetic study

Journal Article · Sat Nov 15 00:00:00 EST 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.08.007· OSTI ID:21212108

Lopez, C A; Viola, M C ^[1]; Carbonio, R E ^[2]; Sanchez, R D ^[3]; Fernandez-Diaz, M T ^[4]

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1. Area de Quimica General e Inorganica 'Dr. Gabino F. Puelles', Departamento de Quimica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina)
2. Departamento de Fisicoquimica, Facultad de Ciencias Quimicas, Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC) CONICET, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)
3. Instituto Balseiro, Universidad Nacional de Cuyo and Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 S.C. de Bariloche, Rio Negro (Argentina)
4. Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9 (France)

La-doped Sr{sub 2}CoWO{sub 6} double perovskites have been prepared in air in polycrystalline form by solid-state reaction. These materials have been studied by X-ray powder diffraction (XRPD), neutron powder diffraction (NPD) and magnetic susceptibility. The structural refinement was performed from combined XRPD and NPD data (D2B instrument, {lambda}=1.594 A). At room temperature, the replacement of Sr{sup 2+} by La{sup 3+} induces a change of the tetragonal structure, space group I4/m of the undoped Sr{sub 2}CoWO{sub 6} into the distorted monoclinic crystal structure, space group P2{sub 1}/n, Z=2. The structure of La-doped phases contains alternating CoO{sub 6} and (Co/W)O{sub 6} octahedra, almost fully ordered. On the other hand, the replacement of Sr{sup 2+} by La{sup 3+} induces a partial replacement of W{sup 6+} by Co{sup 2+} into the B sites, i.e. Sr{sub 2-x}La{sub x}CoW{sub 1-y}Co{sub y}O{sub 6} (y=x/4) with segregation of SrWO{sub 4}. Magnetic and neutron diffraction measurements indicate an antiferromagnetic ordering below T{sub N}=24 K independently of the La-substitution. - Graphical abstract: La-doped Sr{sub 2}CoWO{sub 6} double perovskites have been prepared in polycrystalline form by solid-state reaction. The general formula of these compounds is Sr{sub 2-x}La{sub x}CoW{sub 1-y}Co{sub y}O{sub 6} (y=x/4). XRPD, NPD and magnetic susceptibility studies were performed. The structure of monoclinic La-doped phases contains alternating CoO{sub 6} and (Co/W)O{sub 6} octahedra, almost fully ordered. NPD and magnetic measurements indicate an antiferromagnetic ordering at low temperature.

• OSTI ID: 21212108
• Journal Information: Journal of Solid State Chemistry, Vol. 181, Issue 11; Other Information: DOI: 10.1016/j.jssc.2008.08.007; PII: S0022-4596(08)00435-0; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANTIFERROMAGNETISM
COBALT IONS
DOPED MATERIALS
LANTHANUM IONS
MAGNETIC SUSCEPTIBILITY
MONOCLINIC LATTICES
NEUTRON DIFFRACTION
PEROVSKITE
POLYCRYSTALS
SEGREGATION
SPACE GROUPS
STRONTIUM IONS
STRONTIUM TUNGSTATES
TEMPERATURE RANGE 0273-0400 K
TETRAGONAL LATTICES
TUNGSTEN IONS
X-RAY DIFFRACTION