The Rh oxide ultrathin film on Rh(100): An x-ray photoelectron diffraction study

The surface and interface structure of the RhO2 ultrathin film grown on Rh(100) is investigated by means of x-ray photoelectron diffraction. Experimental and simulated one-and two-dimensional angular distribution intensities of the O1s and Rh3d(5/2) chemically shifted core levels are quantitatively analyzed. The previously proposed O-Rh-O trilayer model is independently confirmed. A rippled buckling of the metal surface is observed at the oxide-metal interface, with a mean interfacial Rh-O distance which is 0.2 angstrom larger with respect to previous findings. The link between the local atomic rearrangement and the overall geometric and electronic properties of the oxide is discussed on the basis of a thorough comparison with the corresponding RhO2 rutile structure. (C) 2010 American Institute of Physics. [doi:10.1063/1.3509777]