English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/123980
Compartir / Impacto:
Estadísticas
Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Título

Strategies for the optimisation of the oxide ion conductivities of apatite-type germanates

AutorOrera, A.; Slater, P. R.
Fecha de publicación2011
EditorWiley-VCH
CitaciónFuel Cells 11(1): 10-16 (2011)
ResumenRecently, apatite-type germanates La9.33+xGe6O26+3x/2 have attracted considerable interest due to their high oxide ion conductivities. Research has shown that the key defects are oxide ion interstitials which lead to the conversion of some of the GeO4 units to GeO5. Consequently there has been a large interest in the preparation of high oxygen excess samples with high defect concentration. This strategy, however, leads to a reduction in symmetry from hexagonal to triclinic for x > 0.4, and consequently to reduced oxide ion conductivity at low temperatures. We present doping strategies to stabilise the hexagonal lattice, while maintaining high oxygen content. In particular, partial substitution of La by smaller rare earths (Y, Yb) is shown to be successful in preparing x = 0.67 samples with hexagonal symmetry and hence high conductivities. In addition, doping on the Ge site with Ti, Nb or W, has been shown to be similarly successful, leading to very high oxygen contents for W doping, e.g. La10Ge5.5W0.5O27.5. In the case of Ti doping, however, there was some evidence for trapping of the interstitial oxide ions around the Ti. Preliminary results on the effect of similar doping strategies on Pr, Nd germanates (Pr/Nd)9.33+xGe6O26+3x/2, are also discussed.
DescripciónSpecial Issue: Workshop on Solid Oxide Fuel Cells: Materials and Technology, Albacete, Spain, 2009.-- et al.
URIhttp://hdl.handle.net/10261/123980
DOI10.1002/fuce.201000020
Identificadoresdoi: 10.1002/fuce.201000020
issn: 1615-6846
Aparece en las colecciones: (ICMA) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


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