Morphology and chemical activity at the Au/NiO interface

We have grown An films of different thicknesses, ranging from 1 to 30 MonoLayers Equivalent, on 10 MLE of NiO deposited on Ag(1 0 0) single crystal. XPS and STM measurements were performed in order to study the chemical activity at the interface and the morphology of the system. The An growth on the NiO film starts in a 2D mode and becomes a 3D island growth after the formation of an almost complete layer. After An deposition, the formation of about 0.3 MLE of metallic Ni (Ni-0) is observed. The absence of significant attenuation of the PE signal of Ni-0 after successive An depositions indicates that Ni does not remain confined to the interface between An and NiO. The density of defects at the surface of the NiO film is shown to be fundamental in determining the chemical activity at the Au/NiO interface. (c) 2006 Elsevier B.V. All rights reserved.