AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS2-MoM

Paper SS2-MoM4
Oxide Nanolayers: Artificial Phases in Low Dimensions

Monday, October 31, 2005, 9:20 am, Room 203

Session: Oxide Surface Structure and Characterization
Presenter: F.P. Netzer, Karl-Franzens-University Graz, Austria
Authors: F.P. Netzer, Karl-Franzens-University Graz, Austria
S. Surnev, Karl-Franzens-University Graz, Austria
J. Schoiswohl, Karl-Franzens-University Graz, Austria
G. Parteder, Karl-Franzens-University Graz, Austria
M.G. Ramsey, Karl-Franzens-University Graz, Austria
G. Kresse, University of Vienna, Austria
Correspondent: Click to Email
Transition metal oxides in ultrathin nanostructured layers on well-defined metal surfaces may form novel oxide phases, that do not occur in nature. These "artificial oxide phases" display new physical and chemical properties, which make them potentially interesting materials for nanotechnology applications. They derive their formation, on the one hand, from the interactions at the interface between the oxide overlayer and the metal substrate and, on the other hand, from kinetic constraints during the growth process. The growth of a variety of novel low-dimensional vanadium, nickel, and manganese oxide structures on Rh and Pd single crystal surfaces has been followed and the surface phase diagrams and the atomic structures of oxide nanolayer phases have been characterised by the interplay of various experimental and theoretical methods (STM, LEED, UPS and XPS, HREELS, ab initio DFT). The influence of energetic and strain effects at the interface is important and determines the particular structures, which are observed on different substrates. The oxide structures to be discussed comprise highly oxidised (nominally V@sub3@O@sub9@), mixed valent (VO@sub1.6-2.09@), and reduced (nominally V@sub2@O@sub3@) vanadium oxide surface phases on Rh(111) and Pd(111) substrates, a c(4x2) wetting layer of an interfacial nickel oxide on Pd(100), which acts as an interlayer to cubic NiO growth, and various manganese oxide phases on Pd(100). It is shown that, in addition to the thickness confinement in the nanolayers, the lateral confinement as imposed by the regular step array on a vicinal substrate surface can promote the growth of novel oxide nanostructures. @FootnoteText@ Supported by the Austrian Science Fonds and the EU STREP Programme GSOMEN.