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Accueil du site > Productions scientifiques > Séminaires à PHENIX > 2009 > Séminaire 16.09.2009 - 14h30

Séminaire 16.09.2009 - 14h30

par Guillaume Mériguet - 14 septembre 2009

Dario Marrocchelli, doctorant de la School of Chemistry, Edinburgh University, présentera un séminaire intitulé

Cation composition effects on oxide conductivity in the Zr2Y2O7 Y3NbO7 system

mercredi 16 septembre à 14h30 dans la bibliothèque du laboratoire PECSA, Batiment F, 7eme étage , porte 754.

Résumé

Oxide ion conducting materials are materials which, whilst in the solid state, conduct electricity due to the movement of ions through voids, or empty crystallographic positions (vacancies). For this property they find use in many technological applications, among which Solid Oxide Fuel Cells are the most important. At the simplest level the ionic conductivity would be expected to increase with the number of vacancies, but this is not the case. Other factors, like the properties (radius/charge) of the cation species play an important role.

In this presentation, I will talk about a combined experimental and computational study on the Zr0.5-0.5xY0.5+0.25xNb0.25xO7 system. This system is of particular interest because, although the number of vacancies is fixed, the ionic conductivity changes by almost two orders of magnitude as we go from x = 0 to x = 1. It therefore represents an ideal test-bed for the role of the cation species on the conductivity. The results obtained allow a good explanation of all the observed properties of this system and lead to a better understanding of the role of the cation species on the material’s conductivity.