PNNL

Abstract

We have studied the electronic structure of oxidized and reduced Ce0·8Zr0·2O2(111) using x-ray photoelectron spectroscopy (XPS). The 50 nm thick Ce0·8Zr0·2O2(111) film was grown on a YSZ(111) substrate using oxygen assisted molecular beam epitaxy (OPA-MBE). This film has been characterized using in-situ RHEED (reflection high energy electron diffraction) and ex-situ XRD (x-ray diffraction), HRTEM (high energy resolution transmission electron spectroscopy) and RBS (Rutherford backscattering spectroscopy). Surfaces of the Ce0·8Zr0·2O2(111) film used in this study is found to be unreconstructed and exhibits the structure of bulk CeO2(111) where Zr atoms occupy the lattice sites of Ce in the fluorite structure of ceria. The extent of surface reduction as a result of vacuum annealing has been reported here in addition to the electronic structure of defect-free Ce0·8Zr0·2O2(111) surface.