Growth and structure of ultrathin cerium oxide films on Rh(111)

摘要: The geometric structure of ultra-thin cerium oxide films on Rh(111), prepared by annealing the metallic at a very low coverage between 0.3 and 1.5 monolayers in an oxygen atmosphere, is investigated using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy, density functional theory (DFT) calculations. STM image LEED pattern indicate that epitaxially grown as ordered CeO2(111) layers aligned to 110 azimuthal direction Rh(111). in-plane lattice parameter measured from appears be contracted with respect bulk ceria lattice. ratio Ce:O for two-trilayer film 1.96:1, which close stoichiometric ratio. simulated basis DFT+U calculations good agreement experimental images.