Formation of the CeY2O3 interface: an in situ XPS study

Abstract We have studied the formation of the Ce Y 2 O 3 interface by X-ray photoelectron spectroscopy (XPS) from a Ce vapor deposi onto a polycrystalline stoichiometric Y 2 O 3 sample. The substrate temperature ranged between the room temperature and 850°C, which is above the cerium melting point (795°C). The shape of the Ce 3d photoelectron lines shows that even at room temperature, an interfacial compound Ce 2 O 3− x forms over a few atomic layers. When the substrate temperature increases, the thickness of this oxidized layer increases. A model based on a diffusion mechanism of oxygen atoms coming from the oxide substrate is proposed to account for the experimental results.