English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/156080
COMPARTIR / IMPACTO:
Estadísticas
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Título

Ag2Cu3Cr2O8(OH)4: a new bidimensional silver–copper mixed-oxyhydroxide with in-plane ferromagnetic coupling

AutorCasañ Pastor, Nieves ; Rius, Jordi ; Vallcorba, Oriol ; Peral, Inmaculada; Oró, Judith ; Cook, Daniel S.; Walton, Richard I.; García Arribas, Alberto ; Muñoz Rojas, David
Palabras claveBond-valence parameters
Sola-cells
Magnetic-properties
Electronic-structure
Chromite catalysts
Crystal-structure
Cobaltous oxides
Ag2Cu2O4
AgCuO2
XPS
Fecha de publicación28-ene-2017
EditorRoyal Society of Chemistry (Great Britain)
CitaciónDalton Transactions 46(4): 1093-1104 (2017)
ResumenAg2Cu3Cr2O8(OH)4, a new Ag–Cu–Cr–O layered mixed oxide, prepared by soft hydrothermal heterogeneous reactions, is reported. The new phase is an oxyhydroxide and presents a structure with alternating brucite-like Cu–O and Ag–O layers connected by individual chromate groups. The crystallographic structure has been solved and refined from high resolution powder X-ray diffraction data and is supported by density functional theory calculations, yielding a triclinic, space group P[1 with combining macron], a = 5.3329(1) Å, b = 5.3871(1) Å, c = 10.0735(1) Å, α = 80.476(1)°, β = 87.020(1)°, γ = 62.383(1)°. Bond valence sums suggest the formulation of Ag+2Cu2+3Cr6+2O8(OH)4, an electronic state fully supported by X-ray photoelectron spectroscopy (XPS) and Cr K-edge X-ray absorption near edge structure (XANES) measurements. Ag2Cu3Cr2O8(OH)4 exhibits bidimensional Cu–O–Cu ferromagnetic correlations that are apparent at much higher temperatures than in other similar Cu–O layered structures, without coupling between Cu–O layers, which represents a unique case in the recent family of silver copper oxides. The role of Ag inducing bidimensionality in copper oxides is therefore expanded further with the presence of chromate anions. Ab initio calculations using density functional theory show that the electronic states involved originate mainly from Cu and OH orbitals, with minor contributions from Cr and the O atoms linking the Cr tetrahedra to the brucitic Cu–O layer, and almost no contribution from Ag. Further modeling of the in-plane magnetic interactions between Cu atoms suggests that the coupled magnetized stripes are responsible for the observed behavior. The results are discussed in relation with previous Ag–Cu mixed oxide phases where metallic behavior or ferro–antiferro transitions had been observed. The structure of this new Ag–Cu–O phase as compared with previous silver copper oxides supports the conclusion that the Ag–Cu layered ordering is favored under oxidizing conditions.
Versión del editorhttp://dx.doi.org/10.1039/C6DT03986C
URIhttp://hdl.handle.net/10261/156080
DOI10.1039/C6DT03986C
ISSN1477-9226
Aparece en las colecciones: (ICMAB) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Casan_DaltonTrans_2017_postprint.pdf1,17 MBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.