Morphology and chemical activity at the Au/NiO interface

Abstract

We have grown Au 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 Au 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 Au 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 Au depositions indicates that Ni does not remain confined to the interface between Au 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.