AVS 46th International Symposium
    Surface Science Division Tuesday Sessions
       Session SS1+EM-TuA

Paper SS1+EM-TuA8
Epitaxial Growth and Characterization of Zirconium-Doped CeO@sub 2@(111) Thin Films on Yttria-Stabilized Zirconia(111)

Tuesday, October 26, 1999, 4:20 pm, Room 606

Session: Oxides: Growth and Structure
Presenter: T.T. Tran, Pacific Northwest National Laboratory
Authors: T.T. Tran, Pacific Northwest National Laboratory
Y.-J. Kim, Taejon National University of Technology, Korea
S. Thevuthasan, Pacific Northwest National Laboratory
G.S. Herman, Pacific Northwest National Laboratory
Correspondent: Click to Email
Doping of the ceria lattice with Zr has been shown to enhance the oxygen storage capacity and the rate of oxygen release, and thus the catalytic properties of noble metals supported on these oxides.@footnote 1@ The ability to obtain a detailed knowledge of the effect of the surface structure and zirconium doping levels on oxygen exchange rates requires high-quality single crystalline materials. In a previous study, pure and Zr-doped CeO@sub 2@(001) thin films were grown on SrTiO@sub 3@(001).@footnote 2@ Due to the good lattice match and identical crystal structure, yttria-stabilized zirconia (YSZ) was chosen as the substrate for the growth of CeO@sub 2@(111) in this study. Both pure and Zr-doped CeO@sub 2@(111) thin films were grown on YSZ(111) by oxygen-plasma-assisted molecular beam epitaxy. After deposition, the films were compositionally and structurally characterized by in-situ reflection high-energy electron diffraction (RHEED), low-energy electron diffraction (LEED), x-ray photoelectron diffraction (XPD), and x-ray photoelectron spectroscopy (XPS), as well as by ex-situ Rutherford backscattering spectrometry. RHEED, LEED, and XPD results indicated that the materials are well-ordered at the surface for zirconium doping levels up to 40%. Furthermore, a +4 oxidation state was confirmed for both Zr and Ce using XPS. RBS results showed that Zr was found to incorporate substitutionally at cation sites in the ceria lattice. @FootnoteText@ @footnote 1@ P. Fornasiero, G. Balducci, J. Kaspar, S. Meriani, R. Di Monte, and M. Graziani, Catal. Today, 29, 47 (1996); Hamada, H., Catal. Today, 22, 21 (1994); Ozawa, M., M. Kimura, and A. Isogali, J. Alloys Comp., 193, 73 (1993). @footnote 2@ Y. Gao, G.S. Herman, S. Thevuthasan, C.H.F. Peden, and S.A. Chambers, J. Vac. Sci. Technol. (in press).