Surface Composition of Layered Ruddlesden-Popper La n+1 Ni n O 3n+1 (n = 1, 2 and 3) Epitaxial Films

Abstract

Layered Ruddlesden-Popper (RP) type oxides, formulated La n+1 Ni n O 3n+1 (n = 1, 2 and 3), have recently been suggested as candidates for IT-SOFC cathodes. The oxygen surface exchange activity is strongly influenced by the surface composition and atomic surface structure where the adsorption and dissociation of molecular oxygen take place. It is therefore necessary to understand the surface and near-surface chemical compositions of the cathode materials. In this work, the surface and near-surface composition of epitaxial films in the RP series was systematically investigated using low-energy ion scattering (LEIS).